not sure but the curve part, but for action, you can get feeler gauge at some serious hardware store. The measurement goes by the thickness of the piece. Each piece has its own thickness imprint on it, in 6/32, 3/128 inch etc.
i got mine from a hardware store at the building near lido, 3 or 4th floor couple years back. Not sure if the shop still there thou. They have lotsa cool tools selection, even thou the price is a bit exp, imho.