What is a Western Field Model M175a?

I'm not sure of the age of this gun, or where it originally sold from, as it was given to me by an aquantance. However,it is similar in construction to most Mossberg shotguns I've seen, it has what I believe was at one time called a polychoke, which is adjustable from improved cylinder, modified, and full choke. HYTRAM It's a Mossberg 385K wearing a suit from Montgomery Ward.