Looks like it came out of an early electronic organ or a jukebox. Not a homebrew. It also doesn't look as if it's been mangled or modified. It looks stock.
In your place, I'd start by replacing all the caps (all but mandatory with a unit this age). All lytics, and especially those "bumblebees," will likely be leaky as a sieve. Any micas or ceramics could probably be left alone, but I see none of those.
From the looks of things, those two small lytic caps may be involved in some sort of simple speaker crossover network. A common and inexpensive practice was to feed the low-range speaker (woofer) direct from the OPT, and feed the high-range unit (tweeter) through small caps like these.
After the recapping is done, verify all resistors; the big power resistor is likely the only one that hasn't drifted off spec. You'll be safe with values that fit within the tolerance rating of the resistor (i.e., with a resistor rated at 10% tolerance, any value within 10% of the specified value should be OK).
After that, verify the OPT and power transformer windings against opens and shorts (including shorts between windings and shorts between windings and frame) with a multimeter at least. Depending on what you find, further testing may be needed.
All of these steps should be completed before you consider powering up.
Keep us posted and good luck on your restoration