Quality kit you've got there

......IIRC the OM-1 was the manual version to the OM-2 which was fully automatic.
I still have my Olympus OM-10 which was fully automatic but by fitting a small attachment (£25 cost at the time) it was immediately converted to a OM-1/OM-2 allowing you to switch from one version to the other at the turn of a dial (the best of both worlds).
I've got the usual 28mm wide angle, 50mm standard issue, 300mm telephoto but my favourit all rounder is my 28-115mm.
Take care of it....very nice