PWK carb "O" ring seals not available, what to use

My 39mm PWK carb has an internal leak on the jet/venturi block. It is a removable part of the carb and contains the main, pilot, emulsion tube and needle jet. The block is sealed to the carb body with a preformed "O" ring assy of complex design. The "O" ring is no longer sealing and all sorts of problems result. This part is NOT available from Carb Parts dot com or anyone else that I can find.

I am looking to improve the seal with any one of the following

1) a form in place gasket
2) a series of thin soft "O" rings that will fit well enough to allow full seating of the part.
3) an OEM replacement part
4) a form of fuel proof permenant sealer on the old "O" ring


I hate to purchase another $350.00 carb just for a 39cent "O" ring.

TIA,

Chris

Well I fashoned a repair (suggested by PK) with PRC (aircraft fuel tank sealant that cures into synthetic rubber) and the old o ring. It seems OK so far! I made sure not to put too much sealant on the o ring so there would not be a risk of clogging the microscopic ports.

Chris