I have around a 1962 (i belive delta) overflow system that has a plastic lock nut using a flat washer. the elongated sleeve on the nut needs to be nearly 5/16 lond to reach the male thread of the waste line that is flush with the tub and does not stick out a few threads like a kholer product. I have searched high and low for this beast and am contemplteing a tooling shop because most every tub is back to back or i would simply replace the entire overflow assembly with something newer.
PLEASE help.