I recently completed a snare project using an NOS Radio King shell bought off e-bay. I has it lathed down to fit a standard 14" head.

However, it seems that the COB Radio King hoops I bought for it are slightly bigger in diameter than conventional hoops so once tightened down, the collar from the head (Remo) slips up past the bottom of the hoop and loses tension.

I measured repeatedly and it's not out of round, just a bit bigger all around than a modern triple flange (I am new to vintage drums).

I know there have been threads about brands of heads being different diameters and there are also the Aquarian American Vintage heads. are the Aquarian heads actually larger circumference than Remo and Evans?

Any other options?