Your right!, there is a open port going to the inside of the crankcase where the base of the pump seats.

My mind has been so focused on researching this with a my computer I've moved away from actually studying the engine itself. It is in fact a combination pump design. I thank you for pointing this out to me, the mystery has been solved and the McCulloch Wildcat specification sheet is simply wrong on the oiler type spec..

Thanks Grumpy!

"You can have any color you like as long as it's black."
Henry Ford