Just a follow-up in case any future reader wants
information. I took a chance and bought an old
Futaba FP-T5FN radio control transmitter, offered
on ebay. It cost $26 plus $10 shipping. I consider
myself triply lucky:
1) The unit had not been used in many years and
the internal battery had leaked all over the
main circuit board, completely ruining it.
This considerably eases my conscience over
tearing up the unit and only using the sticks.
2) The joysticks have 5k pots as required and,
other than a very light coat of fuzz on the pot
cans, were unaffected by the leak and operate
perfectly.
3) As a bonus, the joysticks' physical appearance
very closely resembles those originally used
by Cromemco.
Bill Sudbrink