They're both Mossberg 500's and there are several pages of these in the Blue Book. Most likely one marked with a Montgomery Ward name is going to be a field grade worth $100 for well-used but servicable gun up to $200 or so for one in 98% original condition.
50-150 USD
Approximate value on this shotgun is $130 - $200 depending on condition.
The Montgomery Ward Western Field 16 gauge 550b shotgun is valued at $200 in excellent condition. Fair condition value is $75.
The value of a Western Field model 37 EMJ shotgun will vary depending on the condition. The prices start at an estimated $225.00.
$50 in good condition
The 12 gauge pump Western Field shotgun, M550ABD with a c-lect choke is valued at $200 in good condition. It is valued at $100 in fair condition.
The Western Field 12 gauge side by side shotgun, serial number 30415 is valued at $225 in excellent condition. In fair condition it is valued at $125.
Your shotgun was made for Montgomery Ward, using their Western Field brand. It is a Mossberg Model 183T. Value is around $100-$125, depending on condition.
The Pump shotguns are bringing $150 to $200
In the neighborhood of 550 dollars.
Depending on condition, 150 to 350 dollars. Possibly 450 dollars in perfect condition with low number serial.
75 - 100 dollars in fair to good condition.