Top back panel from a 72 twin. I put a knob on. Sorry missing in the picture. Old 3 prong. A ground wire that is mounted under one of the chassis screws. Huge output transformer. Not sure if this is original to the amp. I recall selling a 64 pro with the same set up.
This amp works and plays. Reverb and trem sound amazing. You will need a FS or a plug.
This is an old amp that has many vintage parts. It may need some servicing or TLC to see heavy use. Cleaning and more stable of speaker connections maybe needed. But this is a fully functional amp that plays. And reverb sounds great. Purchased this a few years ago to mod. But didn’t want to ruin a classic. I bought another roached out twin and built it up.
Please understand this is an old amp. And all old amps have quirks of their own. Its a heavy one.