Thank you Dave! Sometimes trying to put together this car, and growing old, I feel that my brain has lost what little it had in the way of reasoning power. I'm guessing that the O ring acquires the "D" cross section as it ages in that piston bore. Maybe as uniqueness it is a really tough "O" ring, for one thing it will not allow itself to be turn "inside out" like a regular O ring.
Since I know so little of procedure here, Dave, could you PM me on how to order from you? My email is Zeppo2K2@yahoo.com.
Now I just have to figure out the pulley/woodruff key issue when my pulley arrives from Dan. (and then on to steering shaft bushings, heater core mounting repair, passenger door window guide reglue, put the engine in, and see if I can take a drive! Or what else is lurking in that pile of parts?)
Ron