Mirror reflex 3M-5A

Hi, greetings to all, I am new here.
I got a used lens with a Minolta mount, seemingly not an adapter on a M42. The mount is not good and I want to attach a Nikon mount. On description of the lens it says that they have interchangeable backs so I assume it is delivered with the Minolta mount from the beginning.
How can I attach a new mount without an adapter (wobbely) for Nikon F to attach the F4s (like the weight of the combination).
If possible, where can I get an appropriate back?
Thanks folks

Roemer

Hi and welcome!
There are 3 screws around the mount. If you unscrew them, you will be able the remove the mount.
For a Nikon F mount, look for "KP A/N" mount on eBay. You can find them for around 15$.

Btw, it's ZM-5A, not 3M-5A. Зз is Z in Russian.

Hi, thanks for the info. found the 23 screws. will give it a go.

Roemer

As the name implies (ZM-5A) there is na "A" mount at rear verey similar to "T" mount bur without the inner screw ring.
The adapter is hold by three small screws around the adapter ring
Regards
LP
No not move on outer barrel screws once the lens may desalign!