Cat used the throttle and grips called "Gran Turismo" and from what I have seen they are pretty specific to the cat line.
I talked with Dave Liberton about them recently and he thinks that cat was actually making them in house but I'm not real sure about that as Gran Turismo makes/made grips etc for resale, you just never see the cat throttle on anything. He had some NOS listed recently but ran out and was sending out typical chrome metal assy's instead :facepalm: He told me he was going to dig around in his inventory he thinks he has some still but just does not know where and if he found any he would let me know. He bought out cat and others inventories as they went out back in the 70's, from talking to him though it sounds like all the "Important" stuff is long gone and he just has oddball things left over.
heres what they look like (off a cat 350ss I had, of course now owned by Derek :laugh