Thank you for the clues on getting a schematic guys. I agree this looks like something from late 40's, no later than early 50's. Oldest electric organ I have seen so far, of course I am relatively new to this.
I pulled most of the organ apart on Fri. I declined trying to sell to a restorer because I just don;t have the space right now for storing it and I promised the wife I would only be keeping the amplifier. I almost kept my word.
The blower and the soundproofing chamber connected to this, were apparently serving as the Hotel California for a mouse party. It was a bit repulsive the amount of urine and fecal matter present so that portion went straight to the burn pile.

I did keep the electrostatic reed section and I might see if anyone wants it on the organ forum for parts on a restoration project. Since it was sealed in a metal can and the reeds were individually keyed like the Everett models, the mice did not get that far. It is really an interesting piece. I also salvaged a little bit of wood, all pre-ban Phillipine mahoghany I believe, the switch/power distribution box, and pilot light and a few pieces of hardware.
Unfortunately, what I thought might be a reverb unit is just a giant, wire wound resistor. Looks like it may have been used as some type of heater? Perhaps for warming the unit in an unheated church on a cold winter day? It doesn't appear to have any function in the audio circuit. It was just a simple power cord plugged into the power distribution with the ends connected to the resistor. It is probably 10"-12" long.
I am excited to hear that the PT and associated iron is good stuff and I was told when I picked the organ up that it still played with the exception of a couple keys so I assume that it is all good.
I believe it may be best to approach this as a clean sheet build than try to modify it's existing circuits to guitar use. Will be looking for schematics that can best utilize the chassis layout, Chassis will need a good bit of cleanup. I will de-solder and remove all the resistors and capacitors that can possibly be removed.
I have a crude but effective process for removing the old solder. I find heating it to molten state and then giving it a brief blast of compressed air is the most efficient. It makes a mess of splatter, and requires good eye protection it but beats any other method i have tried for working in cramped, point to point chassis with wrapped components
Is an OT used with a field coil speaker such as this suitable for driving a modern speaker? I haven't measured the resistance on the voice coil yet. Assuming I get a speaker with similar ohm rating the field coil just provided magnetic flux boost correct?
I will try to get some pictures of the reeds.