Pulled the printer from the M28ASR to give me a better view of the
keyboard area (but found a mouse nest underneath) and got the
keyboard cover off. Tripped the keyboard clutch a few times and the
stuck keys popped up. Seems to be OK now. Lubricated everything in
sight and put it back together.
While checking out the keyboard from below, someone took a picture
of me:

The big transmitter next to me is a TMC SBT-!KV, 1KW SSB transmitter
from c1962. The transmitter, a TMC GRP-92 & FFR receiver console
and the M28ASR all came out of a cold-war, underground bunker of the
New York State Emergency Operations.
Now to dig into why the motor for the auxiliary reperf smokes!
Have fun,
Duncan
K2OEQ