Well, yeah, except I've just mentioned three different frames that definitely exist, and I imagine there will be more older (60/70s? 30s? Pre WW1?) ones that I don't know about.
The ones that I've seen were probably 60's on, wonder how many pre 60's ones are left and not just scrapped once they were replaced.
The ones that I've seen were probably 60's on, wonder how many pre 60's ones are left and not just scrapped once they were replaced.