Whistling holley 1920

Yes a loose screw would suck, but staked in screws are how the throttle plates in many (most?) carbs are held into the throttle shafts anyway. Brazes or welds would work unless it is on the side of the plate that has to slide out through the throttle shaft slot if you ever wanted to completely diassemble things. A 'no-hole' plate would be best, but you are going to have to re-stake in the retaining screws.

Just as info, BTW, my Holley 1920 does not have a hole in the throttle plate....