I may need a custom screw machined

[Jon A.]

That doesn't surprise me, I've used that sort of thing before without success.

Anyway, that looks easy enough to duplicate, it isn't a far cry from an ordinary set screw. I would use a couple of nuts at the top to help lock one into position in a vise, cut it to size and file the threads off the end, then just use a drill press (if I had one) to drill the hole I want. I'd measure the drill bit first and put tape on it in lieu of a depth gauge.