Yeah, the 1.8 has five or six variants, but my parts books are stored upstairs and I'm too lazy to go up and check. For example, most of Olympus' original lenses had what was called "coated lens elements", cutting edge technology at the time, as good or better than any other glass made by anyone. When technology improved, Olympus elements were made with "multi-coating", then, "new multi-coating"! (Some later lenses (*cough* 85-250mm?) incorporated "ED" (Extra-low Dispersion) glass, but Olympus never touted it's use -- they didn't want customers to know that some lenses were "different" than others!)
While I'm sure other makers had similar processes, Olympus was exceptional for improving their equipment, not only during production, but by redesigning whole models when circumstances warranted. Every few years, whenever a design engineer thought up a simpler or more reliable way to do something, it would be incorporated, and we would get "new version" pages, or "improved parts" notations. "Because that's how Leica did it a long time ago," was never good enough for Maitani.
Olympus' problems were never on the "factory floor", you might say.
I trained on the SRT's and Spotmatics (among many other models) in my youth. All had their failings. Pentax used a "spill gear" design that is notorious for wearing out, making the shutter unreliable, and SRT's.... Well, I don't want to describe how simply putting a twist in a cord makes the indicators go crooked, and so forth. Like many designs, they were needlessly delicate, complex and "adjustable" when superior design could have made all that unnecessary. If someone has never encountered those kinds of problems in their camera, they should count themselves lucky!
Of course, every camera of the age used plastics, rubber and the like, and now plastics are failing, rubberized curtains are cracking, and so on. It happens to all of us!
Years ago at dinner a tech from Japan asked me, "Old cameras were never made to last 20, 30 years! Why you fix old cameras?! New cameras so much better! Get new ones!" I shrugged and said, "It's who we are -- we fix things!"
