Dual HIF6s carbs on a B20E.

Stripped Throttle Shaft Screw
I managed to destroy one of my two carburator throttle shafts. I got a great replacement today (Thanks Rhys!), but I realized that one of the two screw holes on my other "good" throttle shaft is slightly stripped out. What's the best way I can go about securing the plate on that side? As I see it, I could fill hole with JB Weld and put a proper screw in, or I could just leave it loose and count on the split-end screw to stay in, or I could tap the hole slightly larger and put in a standard brass screw secured with the dreaded loctite red... I do want to be able to service the carb normally, but I also do not want to get screwed by a stray screw going down my intake and wrecking my nice B20E...

6-40 vs 6-32 set screws.
I've lost one of my fuel overflow adjustment screws. These little guys sit on the side of the carb and are part of the fuel overflow and return system that prevents a lot of the fuel overflow nastiness HS6s experience... Anyway, the little 1/2" machine screws are the same size and pitch as the idle adjustment screws (which I also need to replace). Both screws are #6, 40 threads per inch (6-40). I need 1/2" overflow adjusters and nut, and 3/4" long idle screws to accommodate my new throttle plates.

After a fruitless trip to two local hardware stores, I've realized that this is an odd pitch and size. 6-32s are very common, but not 6-40s. I might not be able to find any of these 6-40 machine screws from regular suppliers.
So... I could tap the old screw holes to a 6-32 and use commonly available, easily replaced hardware, or I could try and find someplace that could special order some of the correct sizes and hope that I don't have to buy 50 of each size.

Any thoughts or suggestions on how to proceed?