For what it's worth , this was on a packing slip in the box of a stock 200-4r filter I recently bought . . . . .
The standard dash number for the "0" ring is 115 . Nominal dimensions of the ring is 11/16 '' X 78 OD x 332 . These may be purchased from the local Jobber .
Who is the local Jobber ?? I don't have a clue .
Good luck
Gordon