Bill, I've found most of my O rings at my local Ace Hardware store. Perry made a lot of carburetors either as OEM stock, or replacements. John Brodbeck, and John Perry were good friends, so K&B's had Perry carbs for many years. The story is that K&B decided to make their carburetors in house, when John Perry bought a new full scale airplane. The carburetor was the most expensive part of the engine, and K&B decided it was time to reduce their up front costs. Over the years I've run a lot of Perry carbs, and yes the idle disc is very sensitive. Perry carbs are still available.