There were about two types, so I ordered one piece each of the same specification parts

O-ring set looks good☆

Starter plunger
It came with a pin☆

Same dimensions, we’re good☆
It’s a part that works fine if you just hold it in place, but with a pin,
it always contacts the same spot, so the wear pattern becomes consistent.

Polished it lightly and whoosh
On hold until the parts arrive.
