Bruce,
Some people refer to the mechanical, foot starter, as a mechanical solenoid. Are you referring to an electrical solenoid?
If it is electrical, it must be from a passenger car, since 6v electrical solenoids were not used on trucks (except for the 53-55 Hydra-Matic equipped trucks - a starter that might not work properly attached to manual transmission flywheel and clutch housing).
Someone who knows about the 6v automobile solenoid/starter will most likely soon post a helpful answer (certainly more helpful than my answer has been).
Tim
