The oil check for the engine is under the clutch, a hex type nut, screw it out a ways and oil should drip from the fitting. If not, add oil in the large pipe type filler on top of the case by the clutch untill oil does drip out the fitting below the clutch. Rear and tranny fill to level with the pipe plugs opening with gear oil.. Drain engine oil on bottom by oil filter, replace filter be CERTAIN not to overtighten filter.
That is on my 1948 styled A, don't know about unstyled but probably about the same.