I've read your posts with great interest due to my recent purchase of a 1951 or 1952 BR-6f. I haven't found much info on this series/era of amplifiers, so I'm interested in learning all that I can on these amps.
My amp is almost totally original. The only items not original include the handle, 4 capacitors, and I "think" 1 resistor (it's the only one with a tolerance band on it).
Thank you for posting.