Just cut it from gasket paper. Dont use sealant, as you dont want any rtv dags getting dislodged post filter and making their way into the bearings or heads.
At most give the paper a spray with some hylomar to give it a bit of tack
I have a bunch here brand new I am happy to scan.Have considered doing an Oring program in the cnc for these being the gaskets are no longer available..