" I have had oil in my antifreeze"
How did it get there?
While water in the oil is always a problem, oil in an N radiator is not usually a problem.
Anti-freeze has water pump lubricant in it. That's oil. Because it's a flathead, no oil lines are above the head gasket. But, you could have had a slight leak in the head gasket which will produce a sheen on the coolant thanks to combustion gases.
Did it have any performance problems?
What did the spark plugs look like?
Did you do a compression check?
Unless you ran those tests, chances are you did NOT have a problem until you pulled the head.
Get a new gasket.
Use sealer on the studs.
Use whatever sealer the head gasket calls for (some don't)
Torque the head nuts correctly (1/3, 1/3, & 1/3) in the prescribed pattern. Then, re-torque after a 30 minute run.