31 Standard Roadster Top Hardware

[fundytides]

Rebuilding a set of top irons for my 31 Standard Roadster (Canadian Built).
1. Does anybody supply chrome wing nuts that attach the front bow to the rest of the assembly? They are smaller than the wing nuts that are used on the windshield posts and are drilled and threaded all the way through.
2. What is the proper way to fasten the front brackets, that go over the windshield posts, to the top bow. Some catalogs say they are riveted on but the bottom hole is countersunk as if to take a flat head screw and the 2 lateral holes are actually slots (for adjustment?). Do they take carriage bolts like the brackets on my 27 T touring?
As usual, any help is appreciated.