That is a trade name used by Montgomery Ward. Proofhouse.com has a store/trade name cross reference chart.
your westernfield model 40N was made by noble,there original model number was 40NA.
Your shotgun was made by Mossberg for the Montgomery Wards Company(Westernfield).The Mossberg model 500ab is the same shotgun as yours.
Mossberg made Westernfield shotguns and rifles for department stores. My Westernfield shotgun is identical to a Mossberg 500.
Your westernfield model 172B shotgun was made by mossberg.There model designation was model 395K.
Your shotgun was made by savage/stevens for montgomery wards(westernfield).
The Western Field model 600 ERI shotgun was made for Montgomery Wards by Remington.The Remington model SPT-58 is the same shotgun as yours.
No published serial number data
Ward's Westernfield shotgun model 312 was produced by the Stevens Arms Company, which was a subsidiary of the Savage Arms Company. These shotguns were sold through Montgomery Ward retail stores and were essentially rebranded models made by Stevens. The model 312 is a classic, double-barrel shotgun, popular for hunting and shooting sports.
The Westernfield 12-gauge shotgun model M550ABD was produced by the H&R (Harrington & Richardson) Firearms Company. Westernfield was a brand used by the Montgomery Ward retail chain, which sold firearms made by various manufacturers under its own label. The M550ABD is essentially a variant of the H&R Model 158 shotgun, reflecting the company's production during the mid-20th century.
Your shotgun was made for Montgomery Wards (marked with their brand- Westernfield) by Mossberg, and is their model 550. As far as age- no way to tell. IF your shotgun does not have a serial number, it would have been made prior to 1968. <><><> Note to previous poster- Sears did not use the Westernfield brand- that belonged to Montgomery Wards. They DID use J.C. Higgins and Ted Williams as brand names.
It is made by Noble for Montgomery Wards , it is also known as the Noble model 60 for parts reference.
The Western Field model 30 shotgun is a Stevens model 520 shotgun that was made for Montgomery Wards.The value of a Stevens model 520 slide action shotgun is between 75-120 dollars on today,s market.