Convert Hammond K102 (7591s) for guitar

I have just got a nice AO-68 amp from a scrapped Hammond K102 organ. It runs 7591 power tubes. The configuration is as seen in the first pic. The seller was originally just selling the tubes, but he recovered the amp for me too (phew!).

Luckily it's a 220/240V version for the UK, and it's working well. I replaced a couple of bias caps, but it was already working fine with a signal input at the RCA marked 'input'. The gain adjust works in relation to this. I think this input goes to the 12AX7 and then onto the 12AU7. The amp won't work if the 6FQ7 is removed, even though I think this is part of the reverb circuit. The part on the left of the amp with EF86 and 12AX7 is not attached at present.

The voltages on the 7591s are a bit high (450V on the grids and 478V on the plates).

My problem is, I can't find a schematic and I don't understand the whole amp circuit. Does anyone have experience of reworking this amp for guitar use? I just want to see what parts of the circuit to exclude without rebuilding the whole thing. It's made of nice components and there is a choke.

Pics attached for interest and in case this looks similar to what someone else has done.

Hi, I am interested in a schematic as well!

I am borrowing the power transformer for an Ampeg B-15 build.

Are you running the GZ34 rectifier?

I believe that little transformer in the corner is for the reverb unit, not a choke...

Out of curiosity -- since you have this hooked up, is the green PT lead a center tap for the 12v blue leads, or for the 6.3v filament? I am not sure how to check this outside the amp..

If I collect any useful information during this build I will certainly pass it along.

Hi, thanks for this info. I'm away from home at present, so can't check now, except to confirm that I am running the GZ34.