[HAM] Just got a free C2, came with free ISSUES

[Zach Meyer]

Hey list!

Just got a 1954 C2 and JR20 for FREE!  (It feels sooo good.)  Anyway,  
a couple issues I would appreciate some input on:

1) The power transformer on the AO-10 has been replaced.  It was done  
decades ago, and the technician's business card is glued to the  
replacement transformer, which is not stock.  It says it was pulled  
from a Wurlitzer.  The preamp seems to be working just fine, but  
should I be concerned about finding a stock transformer or anything  
else related to what was clearly at issue at one time.  (Why would  
the power transformer have had to have been replaced, anyway?  Bad  
rectifier?)

2) When turning the vibrato/chorus on or off on either manual,  
there's a *POP* sound that is completely absent on my C3.  Is this  
normal C2 behavior or is there something to investigate?

3) The Chorus settings sound great, but the vibrato settings sound  
significantly "warblier" than my C3.  There's also a big loss of  
treble when the vibrato is on.  Is this an issue or just a difference  
in age between the two organs?

4) Lastly, is it true that mineral oil is a good replacement for the  
reverb oil in the JR20.  It doesn't sound half bad (though it doesn't  
really sound half good either!) but there's no reverb.  I'm eager to  
fill 'er up and hear it.

As always, thanks for all the advice.

Zach