what is the deal with my 225 /six compression?

All the compression test tells you is if your rings are good and seling and if your valves are ok. Basically what pressure can be created in the chamber. Generally there will be a specification like say 150 psi and you don't want more than 20% variation cylinder to cylinder. Your numbers are good. The highest readings will be with the throttle open and engine hot.

The oil near the 5th and 6th cylinder, is it coming from the sparkplug locale?

The rocker arm cover is common to leak. Its easy to do just make sure among basic hand tools ypu have a scraper and some red scothbright to clean the gasket surface. While you are in here adjust your valves. Take a feeler gauge with te engine hot and running and slide it between the rocker tip and the valve stem. .010" intake and .020" exaust I believe. Watch out for the change in valve order. It will be exhaust, intake,exhaust,intake,exhaust, intake, intake, exhaust, intake, exhaust, intake exhaust. Might wanna throw a rag on the inner fenderwell, this job can get messy.

After the valves are adjusted check your compression again the way outlined and your numbers might come closer together.