[Herald1360]

From the sound of those valves, the amp from the projector is probably a live chassis one. Fine for a dedicated internal amp in a projector or record player but definitely not fine for a guitar amp without some careful modification and at least the addition of an isolating transformer to feed it whilst allowing the chassis to be earthed.

The circuit you attached definitely shows a non isolated amplifier and one intended to run from 120V mains too. For European supplies there was probably a stepdown transformer which is likely to be a non isolating (cheaper) type. I would guess that about the only useful part you'll get from the amplifier is the output transformer which at least has the merit of being one of the more expensive parts you'll need.

If you can't figure out what went where in a fairly basic amplifier, it doesn't bode well for a safe outcome to this venture without a lot of consultation and advice.