I have a slight oil leak where top cover attaches to the secondary throttle housing. Hoping it is just the gasket for top cover, or is it sign of something more serious?

 

A lot of very old carburetors warp a minuscule amount over time from thousands of heat/cool cycles and can leak. Some areas can be flattened out in a lathe, others fixed with new gaskets and some not repairable. If the leak area does in fact have a gasket trying a new one is a cheap repair and hopefully that is all that is necessary.