Your Western field model 550ED was made by Mossberg for Montgomery Wards.The Mossberg model 500E and your shotgun are one and the same.The Mossberg model 500E shotgun has avalue of between 85-170 dollars,depending on overall condition and a good bore.
No published sn data. 50's or so
Gun shows, gun shops, pawn shops, estate sales, garage sales, book stores, on line auctions.
50-200 USD
The Westernfield 410 pump action model M550ED typically holds a value ranging from $150 to $300, depending on its condition and any accompanying features. This firearm was manufactured by the High Standard Manufacturing Company, which produced various Westernfield-branded firearms for the Montgomery Ward retail chain. Collectors often seek it due to its unique branding and historical significance.
Well, isn't that a happy little project you have there! To assemble your Western Field M550Ed 410 gauge pump shotgun, start by ensuring all the parts are clean and in good condition. Then, carefully follow the manufacturer's instructions step by step, like painting a beautiful landscape, taking your time to appreciate each detail as you put it all together. Remember, there are no mistakes, just happy little accidents, so take your time and enjoy the process.
Numrich has a cross reference list (http://www.e-gunparts.com/crossref.asp). It seems that your shotgun is the same as a Mossberg 500E. I have the same gun and ordered parts from them. Here is the site that has a parts list. http://www.e-gunparts.com/productschem.asp?chrMasterModel=0840z500