I believe what you hae is a Mossberg model 42
Your western Field model 93M-497A was made by the firm Mossberg.The Mossberg model 42C and your rifle are one and the same.The model 42C was made from 1938-1941 By Mossberg and Sons firearm Company.I hope that you find this info of interest.
Made by Mossberg for Wards. Value depends on condition, would range from $50-$200. sales@countrygunsmith.net
your wards firearm is actually a mossberg model 42C that was made by mossberg for montgomery wards(Western field).The mossberg model 42C was made between the years 1938-1941.These range in price from 65-175 dollars,depending on condition and a good bore.
As far as I can tell from my research the 04m-497a is a version of the Mossberg 42. I've found a clip on http://www.gun-parts.com/mossberg/
This rifle was manufactured for Montgomery Wards by Mossberg between 1938 and 1941. It is equivalent to the Mossberg 42C. I have seen rifles for sale with missing sights and in rough condition for approximately $60. Obviously for a gun of this age, if it was in excellent condition, with original papers, etc. it could bring several hundred dollars.
That was made by Mossberg and is a version of their Model 42 rifle. Not sure how you came up with the year of manufacture. Anyway, there is some collector interest in the early Mossbergs that does cross over into the store brands. Depending on originality, options, and condition, value would range from $125 to $250. sales@countrygunsmith.net
50-500 USD depending on specifics.