Mike, sorry I didn't get back to you in time. Anyway for future ref. I installed the linkage on my 59. I had to order a new pedal because mine was missing. Seems like I ordered the stock one, but can't remember for sure. Sorry not much help from me this time.
I like the idea of a cable throttle. Should be able to seal that up better than the stock engineering with the shaft coming through the firewall. I get a pretty cold draft coming in around my pedal and shaft in the winter, even with new felt firewall seal thingys.
STan