yep. I need two ,maybe 3 of the double ended, sort of art deco type that were on the 1937 Dominion Ace. I think the earlier ones were sort of boxy with an x on the outer surface. Mine have a smooth elongated elipse on the outer surface.I also need the upper snare mechanism, complete as well. You can P.M. me.

I know it's an old post, but for anyone still looking:

5/32'' British Standard Whitworth (5/32BSW) 32tpi

at least the later premier lug bolts are, and that fits your measurements.

It's the same thread as Meccano, and I have used meccano bolts in the past, but I assume you're trying for the correct look, so you'd be better trying bolts from later premier.

As far as I know Gretsch,& Ludwig also use 5/32" 32tpi, but I don't know what thread they are as UNC and UNF don't include 5/32"

BSW has a 55 degree thread angle where the UN threads are 60, but in most cases the bolts are interchangeable, although perhaps not as perfect a fit as you'd like,