$399.00 on gunbroker
If its in good condition: $50-$75
The value of a Springfield 20 gauge pump shotgun would actually depend on a number of factors. Some of these factors would be the age and the condition of the shotgun.
The Springfield 20 gauge model 94-B is valued at between $75 and $100. It has a 32 inch barrel, and a 2 3/4 inch chamber.
I would say 100 bucks
The value of a Springfield Model 947 B Proof Tested 12 gauge would actually be dependent upon a number of things. The main thing that would be considered would be the condition.
Gunbroker.com will have similar models in similar condition to which you can compare your firearm.
value of Stevens 20 guage model 94 F
I'd bet that is 311A instead of 3114. Savage/Stevens re-named the Model 5100 as the 311 series about 1942 and discontinued the Springfield name in 1948. Depending on condition, it should be worth between $150 and $250.