Avionics (Radio Problem) Narrowed Down... I Think???

Hi all,

I have posted three times, regarding the radio problems, that have
seemed impossible to identify root cause for:

http://groups.google.com/group/rec.a...09e45844bccf31

http://groups.google.com/group/rec.a...f31af512b6a a

http://groups.google.com/group/rec.a...6bb2d7a73268b6

This weekend, I went up with a friend (more electronics savvy than I)
and we flew to breakfast, troubleshooting on the way. The radio never
worked, from my initial call, to my landing at the destination (used
the handheld as a backup).

He mentioned a past problem he had with the relay switch in his audio
panel, and we slid my panel out to take a look... There is a relay
switch, labeled: AMF Potter Brumfield with a part number of:
R40-E1-X4. We popped out that switch, and he carefully tried to open
it up with his pocket knife. He got it half-way out, but didn't want
to force it, so re-inserted it, but also made a visual inspection for
any obvious signs of defect. Nothing obvious was visible.

After breakfast, we threw it back in the plane and the radio worked
perfectly (for the first time in a long time).

So we're thinking one of the relay connections may have been sticking,
and the slight fidgiting with it, might have helped, at least
temporarily??? I'll keep flying it, and hope that the problem may have
been resolved, but I would really like to get another relay switch as a
standby, assuming they they are relatively cheap? Problem is... I
can't seem to find one, on the web, without going through some
mega-part store with large minimum orders required.

Does anyone have an idea where I might be able to find this part?

AMF Potter Brumfield R40-E1-X4

Thanks in advance for any recommendations! And, thanks to all of those
in the past who provided feedback to this frustrating issue!

Best Regards,
Todd