Are there things I should look for specifically to see if anything is damaged or worn?
I'm going to use it to gig. It was between that and a Hot Rod Deluxe, but someone told me the Deluxe Reverbs are better and sound better.
A few things to be aware of if you're new to tube amps:
But first - remember this - around 90% of players NEVER visit forums like this and don't know a thing about proper amp maintenance - because manufacturers DO NOT specify it in the instruction manuals! They assume amps will be sold before the warranty is up and it's not their problem. So very, very few players are aware of these things!
1. ALL newly purchased USED tube amps - even if just a few years old - should go to a tech for a checkup. You have NO idea what condition it's in electronically.
Virtually every used fixed-bias amp (a type of electronic design - and the Deluxe Reverb is one) I see needs the power tube bias adjusted for best tone and/or the power tubes are WAY out of balance and need replacement - and every time they are replaced the bias needs to be checked and usually adjusted (weirdly, "fixed bias" means it can...and needs to be...adjusted any time new or different brand/model tubes are installed. It's a very inexpensive job.
2. Never gig without a backup amp. Not necessarily because the amp is a bad amp, but tubes are made of glass and are fragile. Rough handling by others can cause problems. Tubes can fall out. Mic stands can get knocked around and break tubes! As a player and tech I have seen just about everything - and everything DOES happen sooner of later - maybe not to you, but have a backup on hand.
3. ALWAYS carry spare fuses, a pair of spare power tubes, and one of each type of preamp tube. And a flashlight. Tape spare fuses to the inside of the cabinet.
4. ALL tube amps need periodic service. Preamp tubes can last for 10+ years; power tubes 5-10 years unless they are either REALLY cheap or always pushed to the limit. Electrolytic filter and bias capacitors have a service life of roughly 15 years (the ones in reissues are generally NOT the same quality as used in the originals, which were good for 15-20 years).
They MUST be replaced! When they get old they can fail without warning, and a blown power filter can seriously damage the amp. Find out how old it is, and when it hits 15 take it to a qualified tech and request replacement of the filter and bias caps. You HAVE to ask - not all techs automatically do this stuff but it's critical to the life of the amp.
5. If an amp is over 10-15 years old I suggest asking if you can have it checked out by a tech BEFORE purchase. While it's less likely that a reissue amp will be "hacked" (badly modified and requiring restoration) it's not uncommon with older amps. And as previously noted, most older amps have not been properly serviced.
You can't tell much about the "condition" of any tube amp by looking at the outside. Many of the most beaten-up amps physically are the ones that have been electronically well-maintained - and many "pretty" amps, especially older ones, have NEVER been properly serviced!
You might want to print this and take it with you to the tech.
Hope this is helpful.