According to Theskyiscrying on the Super Champ site, Fender's cover for the Champ 25SE is a better fit than the Hot Rod cover. He/she emphasises it has to be the Champ 25SE and not the plain Champ 25. 

http://www.tukicovers.com/

Or

http://store.amplifiercovers.com/    ($39 US in April 05)

or Susan's Slips, or D2F on eBay. 

• The basic sound! Very musical! You can centre all the tone controls and still get a listenable sound.
  
• All-valve (tube) signal path
• Future-proof; uses only very common valve (tube) types 6V6GT, 12AX7 (=ECC83) and 12AT7 (=ECC81) of which good-quality brands are in current production and will probably still be widely available indefinitely. Couple that with the builld quality, and the truth is we don't really own these amps - we're just looking after them for the next generation.
  
• Unbelievably low-noise operation (hardly any hiss, except in 'lead' mode), which is why they're popular for recording (I've found a lot of studios on the web who have one), and you can do quiet practice without losing too much tone. Also useful in church, where the atmosphere may go from loud to very quiet - not the time for the sound of frying eggs coming from the backline.
  
• Extremely strong construction - welded metal chassis and dovetail joints in a real plywood cabinet. But not too heavy.
  
• "Point-to-point" wiring (better described as handwired with eyelet board; no printed circuit board),  making for ease of modification, ease of repair and physical reliability. The 'physical reliability' idea is based on the fact that the controls, audio sockets and valve sockets aren't mechanically mounted on the wiring board. Therefore if the amp rolls down a flight of stairs, you may have to replace a few knobs and pots, but no mechanical shock is passed on to the heart of the amp and you won't be left with a PCB cracked in two.
  
• Actual reliability. As of April 2011 I've been in touch with over 300 PRII owners, mostly longterm owners, some over 20 years. One appears to have given up on his but he won't tell me what the problem was. Other complains of any trouble at all, and that's not the nightmare-scenario intermittent fault but a straightforward 'stopped working' which I hope a tech has fixed for him by now. One was sold on eBay with a different output transformer becuase the original had failed. No-one has ever said 'had one of those, but I couldn't trust it'.
• Loud for 22W. Brace yourself.
  
• Fixed-bias, the amp design which gets the most power from output valves. This is probably the loudest 2 x 6V6 amp on the planet, unless someone's made one with an even higher plate voltage or used ultra-sensitive speakers. (NB fixed bias is a misleading name; it can be adjusted.)
• Conservatively-rated transformers. They will apparently deliver enough power and stay within safe temperatures even when the amp is modified up to 35W. (That's the 6L6 mod - see here.) Transformers are expensive, so this level of  reliability is reassuring....  
• Solid-state rectifier, so big bass and no "must I?" hesitant response when you ask for a big chord at high volume 
• Depending on the quality of your power (output) valves and the bias setting, you can get marvellous overdrive tones once you turn the master volume knob over 6 or 7 (approx) - or earlier with the mid boost selected. 
• Big variation in tone; bass, mid, treble, presence, plus mid boost switch and treble boost switch 
• Versatility - people are using it for blues, metal, country, jazz, blues, even amplifying classical guitar. There must be better jazz amps, better metal amps, etc etc, but this amp does them all convincingly. For jazz I plug in my f-hole guitar, turn the volume (input gain) down to 7,  treble down to 5 and the middle up to 10.... hey presto; instant 1950s. 
  
• Built 1982-86, so this range of amps were the last to pass through Fullerton. When CBS sold the firm to the management buyout team, the factory wasn't part of the deal. The subsequent (hack, spit) Red Knob range was built at the Sunn factory in Lake Oswego, Oregon; a charming spot, I'm sure, but less associated with vintage amp mojo, if that's important for you. Although (Nov 2011) I've just learned in Tom Miller's excellent book "The Soul of Tone" that the chassis of most PRIIs were wired up in Fender's Ensenada, Mexico factory. If you dismantle the amp and find "Princeton Rev II M" inkstamped on the side of the chassis, that M stands for Mexico. Sorry if that diminishes the mojo for you....
  

• The reverb drops away when you select the 'lead' effect.
  
• On a channel-switching amp, you would expect  2 channels with separate tone and volume knobs, so you had real control over the clean sound, the overdriven sound, and the difference in tone and volume between the two. This is not a channel-switching amp - it's a single-channel amp with a switchable 'lead' pre-amp distort effect - the effect is separately adjustable for how much volume but not tone. If you use the input gain (volume knob) to control the amount of distortion, it affects the clean volume too.  In this range of amps, 22W and real channel-switching came on the Deluxe Reverb II (which Paul Rivera regarded as the pick of the range).
• No standby switch. With the solid-state rectifier, this means when you switch on, the valves/tubes get the high voltage supply before they warm up. Some folks claim this shortens the valve life. You can reduce this effect on the power valves by turning the master volume to zero before switching on. A 2-position power switch could be a solution.
  
• Solid-state rectifier, so (unless you modify it with a B+ resistor or a Weber Copper Cap) it won't do the 'sag' type of compression/distortion associated with valve rectifiers at high volume.
• Fixed-bias output stage, so you don't get the springy compression effect which cathode-bias amps give at high volume.
  
• Conservatively-rated output transformer means it's probably not going to saturate, so you're not going to get the kind of overdrive distortion associated with that. I'm not experienced enough to tell the difference between that kind of distortion and power-amp distortion, and I'm still happy.
• Some regard the 'lead' effect as a waste of space, even though it is achieved with valves; nasty buzzy preamp distortion -  it's intended to simulate warm, welcoming power amp distortion, but it doesn't really. There is no control knob for how much distortion you get - only the volume while in lead mode - and the tone controls only affect the sound before it's distorted, not after. There are a dozen distortion pedals with better sound and more control. PS Sep 03 - since I fitted screen-grid resistors I'm beginning to like the 'lead' sound more. But the lack of adjustability means I'll probably stick with overdrive pedals for gigs. PS Feb 06; replacing v2 and v3 with used prestige old-brand valves from eBay has made the lead sound much, much nicer actually useful in front of people. Keep valve-swapping - you might get lucky. PS Nov 06; made myself a speaker attenuator so I can max the output power and then control the volume reaching my ears. 6V6s in overdrive is the way to go.
  
• Some amps have the knobs recessed within the overall outer dimensions of the cabinet . This one doesn't, so you have to be careful not to hit the knobs when loading it into vehicles.
• No effects loop (but the amp is so quiet anyway, it doesn't matter...)
• No headphone socket
• Nobody likes the 'line out' facility
  
• Some people say this amp is no good until the original loudspeaker is changed for a Weber, Jensen, Celestion, or whatever. I now have a Jensen but still loved the amp with its original speaker.
  
• Built 1982-86, so could be due for replacement of the electrolytic capacitors (a 'cap job'). Weak bass response is a clue to this, though that might also be caused by elderly valves.

• Nigel Tufnell has one which has never been plugged in
• All PRII owners know a secret handshake which helps them buy things on discount
  
• If you hold one up to your ear, you can hear South Pomona Avenue
• If you pull the mid boost while setting mid to 2, it opens up a whole secret game level with zero damage and infinite reloads
• There is a secret Rivera tone circuit which is only activated when you connect the footswitch
  
• No-one knows how good they are, so they're cheap
• PRII ownership makes you more more intelligent and attractive (hi, Ken)
• Never say "Princeton Reverb Two" in polite company in Uzbekistan, as it sounds exactly like the local lingo for "I wish to marry your older, uglier daughter".
• At a jam / gig / battle of the bands  last week / last month / last year, my PRII / my friend's PRII / some guy using a PRII blew away the other guy's Marshall 100W 8x12