David,
That looks like a run of the mill trap grade model 12. The stock is fancy American walnut, which was standard. I had one very similar, except that mine had a monte carlo stock. They were available stocked either way. They were very popular on the trap fields, and were almost impossible to wear out. Mine cost 160.00 in about 1958, but I now see them regularly at gun shows priced at 1000.00 and up.