Nice score!
Essentially, you've got a Champ! Not as much power as a Fender Champ. I'm guessing 2-3 watts instead of 5-6.
The giveaway is the tube lineup and only one transformer. You've got one tube that's probably a 6V6 or 6W6 that would be the output power tube. Another tube would be a rectifier and the last a preamp tube.
Since we only see one transformer the one must be an output transformer. This means the power supply runs directly from the power mains with no isolation or voltage stepup from a power transformer. There will be a capacitor isolating the chassis ground from the power supply ground. If it fails the chassis will be hot with line voltage. You could get a bad shock!
Getting a tech to add a transformer would be a good idea! Still, although everyone will tell you scary stories we should remember that for years and years this was a perfectly legal and common thing to do and history doesn't have stories of millions of people dying like flies from radios, tvs and small guitar amps.
In front of the transformer on top at the left in the picture is a large can mounted to the chassis. It contains filter capacitors for the power supply. They smooth out all the hum after the rectifier has done its job. Over the years they dry out - it's just the way they're made. When they've gone bad they need to be replaced. Meanwhile you will hear a horrible amount of hum! After the cap job the amp will be good for another 20 or more years.
It pays to keep your eyes open, eh?:smile:
:food-smiley-004: