Rick, yes, here are two options .. Before I closed shop last year, (www.oldoutboardbarn.com) I have restored approx. hundred outboards and used two outlets for new or NOS parts .
First contact Jack McDowell (SeaWay) They have 7 million NOS parts .. I was surprised what they had in cowl gaskets. 800-332-0803 EXT.2021 Tell him. TK sent you.
2nd option: Peter McDowell (No relation to Jack) Peter has the bulk Gasket material … http://www.nymarine.ca (Canada) Email .. peter@nymarine.ca phone .. 905-470-7705.
A part number would help but not necessary … Hope this helps TK