I got out my assortment of gun screws and the threaded hole is definitely a 6-32 as opposed to the 8-32 that I’ve been told should fit the factory unit. Of course my Brownell “gunsmith screw assortment” has only one inch long screws with Fillister heads. I just heard about someone who still has the Safari units, but only the whole unit, and they are in the Netherlands! This is turning into a quest rather than just a search!

Once again thanks to ll who have helped and provided information.

Froggie