I mulled over the problems of adding cruise control to my 47 DeSoto (a real mind game). Cruise control:
o Would Need 12 volts, 10 to 15 amps. Either convert the whole car to 12 volts, a large project, or get an inverter, which would draw up to 30 amps from the 6-volt system, or add a 12-volt alternator for just the new stuff. Whew. Starting to gert complicated. And expensive.
o Would need slack in the pedal-to-carburetor linkage, so that the cruise control module could open the throttle without pulling down the pedal. At present, a large spring closes the throttle and pushes up the pedal when the foot is removed. The linkage would have to be reworked to provide the necessary slack, and a separate spring would be required, to close the throttle. I came up with numerous ingenious ideas, each requiring careful design and fabrication. (We don't want the throttle staying open.)
But wait! The problem is the right leg getting tired from working the gas pedal on the occasional extended trip. (For me, an hour-long trip is beginning to be extended.)
Why not push the pedal down by hand? What do the handicapped do? I saw a portable pedal pusher available for about 180 bucks. Why, I could make something similar from junk (precious recources) around the house. Stick, flexible connection to a small base, and lugs or downturned edges of the base to keep the base from slipping off the pedal. Place the base on the pedal, rest the stick against the edge of the seat cushion, and push and pull as necesary to modulate the speed. Lift off and set aside to resume foot-pedaling.