Ah hah ! I think I've found it !
As for the air pump, mine seems to be in O.K. shape, but what I did find is that my model 1976 230, is supposed to have a vacuum pump (located over top of the power steering pump) and mine seems to be missing or gone! This could be why I've been having all these idling problems since I bought the darn thing.
Thanks, for pointing me in the right direction !
1976 230.4 W115