Well, we seem to have a consensus -- restore that tube gear as-is!

One source of tubes and other parts not mentioned is jukebox supply
houses.  There's a thriving hobby business in jukes of all eras, and
any tube that was used in jukes is readily available new, usually at
reasonable prices.  So are phono cartridges (pickups) of all eras.

Robbie mentioned distortion caused by the triode volume control tube
in his Allen organ.  I had the exact same problem in a Kimball photo-
electronic organ.  A more authentic fix would be to rewire that one
circuit around a 6BE6 pentagrid converter tube, which is specifically
designed to multiply two signals.  This tube was used in almost every
radio made after 1950 and is a dime a dozen.  It and previous versions
were used in many jukebox amplifiers as automatic volume controls.

I will conceded that original electronics (tube and transistor both)
aren't always the best designs.  That Kimball sounded a lot better when
I jacked it into a "modern" tube hi-fi amp and bypassed its own amp and
speaker.  But its original "mellow" tone is what people liked in the
'40s and '50s, before the rediscovery of Bach and tracker action, so
it's an authentic representation of musical tastes of its time and
should be preserved.

Mike Knudsen

 [ That's a good suggestion, but I also want the attenuation (decibels)
 [ to be linear with the control voltage, for MIDI use.  I'll hide
 [ the I.C. in the swell-pedal housing.  ;)  -- Robbie