Thanks for the comments.
Yes, it was a very fortunate find. I had been wanting an MX, I just could not bring myself to buy one on the bay. I had made several passes through the flea market that morning, and had bought a lot of other camera gear already, and thought I had found it all. On the last pass before leaving, I just happened to look over to a table and saw it there. I was in disbelief when the seller said $5! I couldn't pay fast enough, to say the least. I put new Goodman light seals in it, reglued one of the cover panels, and have almost finished an initial roll through it. The 40mm came from a resale shop. There's some fungus inside 🙁 that I need to try to clean, I just can't get the front nameplate ring off (haven't had the time to make a serious effort really).
Really liking it so far....it's kinda drawing me away from my Olympus OM's........ 😱