My local rigger just shook his head and said "How about a new stick? For only...."
The mast is over 65'' base to mast head, and tapers dramatically down. This was the early days of the "Bendy" masthead rigged boats. The sheeves are closely spaced, between sections of aluminum reinforcements. They are 1/4" wide, just big enough for the wire, but no way a rope sheeve will fit.
I guess I will trust the wire/rope splice for now, and continue to advise all foredeck crew to make sure they always wear gloves when handling the wire.