Air compressor check valve, 1/2" Compression x 1/2" MPT with 1/8" hole; plug hole if not needed.  https://mastertoolrepair.com/1-8-blk-steel-plug-s-h-100b6e/ If the small unloader (bleeder) valve on or under your pressure switch leaks constantly...

Plastic plug for the piston pin (two used per piston).

Washer for the flywheel bolt.

Pin for the piston. One used per piston.

Old Part Numbers: SSW-7367Strain relief for air compressor power cord going into the pressure switch housing.

Old Part Numbers: 265-16 265-16-1 replaces 265-16

Vent filter for the pump crankcase. This fits into the top of the cylinder.