The back red flag issue may be the revolving back... perhaps not an RB Pro S?.. or a stuck pin in one of the chrome tits. They should move freely when off camera.
The body issue... well I'm not quite sure I understand what you are describing. It sounds like you cock the body and the lever doesn't return? A stuck lever has several causes n cures.
One is the spring may be broken. Another is an obstruction inside the body preventing the lever from returning. Yet another can be a faulty govonor. And yet another can be a bent lever inside. Oh and lets not forget the other possability... the drive gear could have slipped it's adjustment... or the shear pin is begining to strip but hasn't let go yet.
As you can see the only way to determine what the problem might be is to have the camera in hand and possably open her up.
First I'd start by removing the film n rev back, then the lens if you can. If any of these releases the lever, it is npt the body that needs attention. Take a look inside the camera, the slot the mirror arm goes into?... see anything sticking out or odd there?
BTW are your seals gummy n need replacing anyway?
Where are you located? That may help in finding you a reapir person to look at it.
Yes replacing the body is cheaper but it will more than likely need seals n service anyway, adding to the cost of replacement.
The cost of a CLA is about the same as a replacement body but the one you know is always better than the one you don't. A CLA will give you quite a few years of relaible service as opposed to an unknown camera of questionable background, starting anew.
If you need more details or want to try opening it yourself, PM or e-mail me?