Yes I used Grainger in a pinch the other week for 9mm External Retainer Clips or the .010 throttle sleeve.
I say pinch as there is a fastener commercial supplier that has a lot of cheaper prices. I pulled the head off to check the piston size and type
it appears to be a .061 with a small squish cone the short plug almost fits flush.
I really need to buy a pressure gage there appears to be no loss past the piston after a few mins with this simple test also oiled the head threads prior.
Engine has good pop and compression.
Heres a pic.
