Model12Win,
You have a Model 195 Mossberg manufactured between 1954 and 1963. The specific model is probably 195K-A. I have seen some convert these into reasonable turkey-shoot guns, although I would not. It is not a junk gun.
I have a model 190 Mossberg which is the same gun in 16 ga. (with the C-Lect-Choke but w/o the rear sight). This was my fathers gun purchased in 1953 and last shot around 1960. I like the very smooth operation of its bolt. I used it for Phesant hunting as a youngster. I gotta pattern it sometime soon to see how the C-Lect-Choke works.
I believe NMCA (National Mossberg Collectors Association) is still around Try
www.mossbergcollectors.org or 636-937-6401 for parts and information.