It's usually not hard to find a parts OM-1 to be the donor for something like the self timer lever. Apart from that, I'm guessing Nortown can do the job. I agree that spending the loonies for a CLA is worth it. The OMs have lasted for over 30 years with little or no maintenance, so a tune-up should give you another 15-25 years service.
John has my nicely-brassing OM-2 right now, and when he's done my chrome OM-1n will go to him. Then an OM-2n, then ... lol. He's also done a 35SP, a 35LC and an XA for me. Hey, he should buy me a drink!