As freebird after such an overfill it takes a while to burn off all the excess oil in the exhaust and the exhaust must be at operating temperatures for this to happen.
You also said it has been smoking somewhat before hand too which is probably worn rings and cylinder. This can be the cause of the excess oil coming from the breather as there can be excess blow by. The best way to determine if this is the case without visual tear down inspection is the leak down test. There are several possible causes for excess crankcase pressure rings and cylinder wear are one but worn valve guides can cause this especially the exhaust as exhaust gases bypass the valve guide. Now a leak down test will not show worn valve guide(s) as it primarily tests the cylinder condition, head gasket and valves seating.
