Is there a distinct marking on the gun that would tell you what model matador it is?
Their were at least three models of Matador. Models I, II & III. Should be so marked on the barrel. If it simply is marked 'Matador', I would assume it to be the first model.
I have a Model II, 20ga., 3". and so marked. It actually came a 'proof certificate'; stamped, singed and embossed, inscribed w/ the date it passed it's proof tests (Oct. '64), the proof marks on the certificate correspond to the proof marks on the barrels and water table. The certificate carries the basic specifications and serial number as well.
Mine has a little engraving and color case receiver. Selective trigger & selective ejectors. Carried it upland for a decade. It was my dogs' favorite. Classy little guns.
Dog has long since departed for happier hunting grounds. Not much game around these days, but I'll shoot an occasional round of trap w/ it.