So after buying this thing when the owner said all transistor no custom Ic's, I have tested just about every component with my comp checker and found just 2 parts left, philco pa71239, if that isnt an odd ball ic what is, I've been duped.
I guess its a very early op amp, google doesnt even bring any hits, if I had some idea of what it was I'd have a look at stuffing something else in maybe on a bit of veroboard, 741's probably werent out when this thing was put together.
Might even be a nuvistor, that would be fun to replace.