Help me identify an amp

Tubes for Hifi makes the kit similar to these amps called the VTA ST-70. Also have a ST-120 version. All their stuff are modifications to the original Dynaco gear. I’m sure they could help you source any parts you need to replace and also help diagnose any issues you are having.

Man, this should be in the HI-FI hall of fame.  I would love to hear what it can do after you get it in working order.

8417 are out of production and unavailable. Quicksilver used to offer an EL34 mod for their 8417 monos.

Good testing 8417's are still available for $400-$500/quad, though I would advise picking up spares/matched quads in a timely manner as they are considerably more rare than good vintage EL34's (which also run around $400-$500+/quad).

DeKay

Looks like an old Dynaco ST-70K kit.