I would begin by checking the flame trap. Build up there will allow crankcase pressure to increase and force oil out at the engine seals.

If you don’t have a new insert drilling each hole with the appropriate sized twist bit will open things up. Also check the hose that connects the flame trap nipple to the intake manifold. Make sure the nipple is open as well as the brass fitting that the hose is connected to.

You can check the oil separator box by attaching a piece of hose to the top and blowing into it (after removing the oil cap). Air should move through that without any resistance. They can be cleaned but that is not necessary if they are not restricted.

I always check the condition of the crankcase ventilation by removing the oil cap with the engine idling and holding a sheet of paper over the opening in the cam cover. There should be enough vacuum to hold the paper down over the opening.

If the flame trap or its associates are clogged or restricted the crankcase seals are under a lot of stress. This can actually dislodge the front or rear main seal and really spoil your day.
--
Any twenty minute job is just a broken bolt away from a three day ordeal