Ok--I solved the problem with the radio!

Yes, it had been modified. Someone grounded pin 10 of the PPL chip and
fiddled with the VCO for above-band operation. I removed the jumper on
pin 10 and then used a frequency counter to realign the VCO. Also, the
output power was a bit high, so I adjusted the modulation circuit to
make it operate at the legal limits for AM and SSB.

Thanks for the advice. It was helpful.

-Dave