Due to an injury I received I have to install hand controls in my comet. Does know of someone who has done the same to an older vehicle and how well it worked?
I've seen those in older cars when I was growing up, so it has been done. IIRC, the ones I saw used a motorcycle type throttle mounted on a lever that was also the brake. Good luck on however you try to do it.
I helped install them on a friend's Monte Carlo in the '80's. That type used one lever on the right side to operate the brake and accelerator. Up & down controlled one and for & aft controlled the other.
A friend of mine has them in a Vega that he races, so I know it can be done. Unfortunately, I've never really looked at his car to see what his setup consists of. Our season opens next weekend, and if he is there I can try to get some pics. Can't promise he'll be there though, but I'll get pics if he is.