Do i understand that the oil is coming from the plate where the lever comes out of the engine? There is a small gasket under it, you may just need to replace that gasket. A small note, under that plate there are 2 springs that attach the arm to the govoner lever(s), these 2 springs are a total pig to re-attach without also removing the stop cover plate. It can be done with a pair of pointy nose pliers and a second set of hands.
I cheated, i used some red high temperature silicone on mine, as the “full gasket set” did not contain that gasket.
I hope this is of some use, as i have just finished re-assembling a V1702 engine and some of the information is still in my head, well for now at least...