While rethinking what I've done with this set I need to deal with one issue at a time. First issue is the wiring of R41, replacement of C37 and C39, and the destruction of the H-size pot. Everything I've said is based on assumption and memory (or misassumption and forgetfulness) from 10 years ago.
I'm going to post here several 17T1 and 19A1 schematics. I'll follow that up with photos showing what I really know about these components. Patience, please...I have to write everything offline first because of my slowness I can't even write a quick response without being logged off.
This is overlay of the Rider 19A1 schematic (Red) and the Telaides 12T1 (Black):
Adm 17T12 5000 by
H Boyars, on Flickr
Telaides 17T1:
Adm 17T12 5005 by
H Boyars, on Flickr
Rider 19A1:
Adm 17T12 5010 by
H Boyars, on Flickr
Sams 19A1:
Adm 17T12 5001 by
H Boyars, on Flickr
Figure 59 19A1 (I don't know what publication this is from):
Adm 17T12 5016 by
H Boyars, on Flickr
Hand-drafted 19A1 (I don't know the source of this one, either):
Adm 17T12 5014 by
H Boyars, on Flickr
R41 C37 C39 H-size pot in three different schematics:
Adm 17T12 5018 by
H Boyars, on Flickr
Original R41 (It definitely connects to V12 pin 2):
Adm 17T12 5017 by
H Boyars, on Flickr