There may be a few NOS throttle cables out there in private hands, but, none of our favorite parts vendors have any.
So, I have bought this NOS cable with good rubber boots from ebay. I have no idea what it is for, and there is no part numbers on the box.
Doesn't matter though, as both ends of it are identical to the carb end of the M715 cable.
At 53 1/2" long, I can cut it in half and get two M715 cables out of it.
I'm going to cut them to length, turn new ferrules in my lathe and crimp them on at the firewall end of the cable.
Pictures of the process forthcoming.