Again no schematic but the third picture in post #1 looks identical to this one on the site mentioned by Alistair D
http://www.vintagehofner.co.uk/brita...er/west21.html
c1956 WATKINS WESTMINSTER AMPLIFIER COURTESY OF MICHAEL KERR, ESSEX, ENGLAND:
and the internals:-
http://www.vintagehofner.co.uk/brita...er/west19.html