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!
