tone generator capacitors

[Ken Williams <kwilliams@sh-gpl.ti.com>]

   I'm new to all this tone-wheel organ stuff and have some questions
that may have been answered already, but the answers have slipped by me.
I bought a 50's model M3 a few months ago for $150. The case is in perfect
condition (the guy I bought it from called it white maple). Inside, every-
thing seems to work fine including vibrato/chorus, precussion, etc. The
only problems are a pretty good 120Hz hum with the volume all the way up
and one harmonic is missing (which jumps from note to note depending on
which drawbar is pulled out). These, I can fix with little trouble. I have
some questions though. I keep hearing mention of the replacing of the tone
generator capacitors. First of all, what function do these capacitors 
perform? What capacitor parameters degrade over time and how does this
affect the sound? What type of capacitors should be used for replacement
and are their values critical (must they be exact values with low %
tolerance)? What is special about the capacitor kit sold by Goff? What
is the price for this kit for an M3? Is there some special procedure for
replacing them besides yanking the old ones and soldering the new ones in
place? Will I really notice a difference in the sound?

Ken Williams