Either way, no problem. These have a left-hand thread - bear it mind when you are fitting it!
Idle Gear Hairspring Spring for Olympus OM1, OM1N, OM2, OM2N Film Camera
Olympus OM SLR Motor drive cover for OM1 OM1n & OM2 OM2n original
Olympus OM Prism, no staining or damage fits OM1, OM1N, OM2, OM2N, M-1, only
Olympus OM SLR Motor drive cover for OM1 OM1n & OM2 OM2n black versions