Originally posted by Just1MoreDave Or look at cameras that someone can show have been serviced in the last few years. That might be cheaper overall than purchasing a random camera and getting it serviced yourself.
That's a point I was going to make, too. A decades-old film camera is bound to have an issue of some sort, usually more than one. Light seal problems are a given, I think, though that's a relatively easy fix. But there are other problems that may be less evident.
Of those three cameras, the one I would NOT pick is the Minolta SRT-10x . . . but that may be just my experience. First time I picked up an SRT-101, I found my right hand bumping into what I'm remembering as the depth of field preview button at the lower side of the lens mount. I'm sure others know more about the quality of the Minolta bodies than I do, but that 101 felt clunky to me, on the low end of the ergonomic scale. I'm sure that colored my perception of Minoltas for the rest of their production years.
Someone mentioned how easy it is to find K-mount lenses, and how an adapter lets you use m42 lenses on K-mount bodies. So a K-mount body is a good choice, though an m42 body is a good second choice--though a random m42 body would most likely be older than any K-mount body. Then again, I suppose the difference between a 40-45 year old camera and a 50-60 year old camera wouldn't be that great in terms of condition.
Anyway, if possible, try holding and dry-operating the different brands and models you're considering. What feels good in the hand will be more fun to use, and you'll use it lots more in the long run. And what feels good to one person may feel awkward to another. I think that's one of the most important considerations in buying anything, really, be it a pen, a camera, a knife, whatever.
Good luck!