Wester Field Shotgun SB-100A

Question
QUESTION: Hi,
My father is passing me his never been fired Western Field 20 Gauge, SB-100A, Full Choke, Chambered for 3" (?Magnums?)  I cannot seem to find any information on the manufacturer (Stevens,Mossberg, Savage, etc.) for this specific model/gauge.  Any assistance in the background of this gun would be appreciated.
Thank you

ANSWER: These were the trademark guns for Montgomery Ward. Your gun was made by Savage/Stevens, so if you needed parts that would be where you would cross-reference.  If it is chambered in 3",you may be able to but I would hesitate to use magnums, although they are usually good solid guns. Thanks for the question.

---------- FOLLOW-UP ----------

QUESTION: Thanks,
On the cross reference, is there a specific model match w/ Savage/Stevens based on the SB-100a that I would use or did they produce just 1 20 gauge, 3" full choke barrel model during the early/mid 60's?

Answer
Numrich Armns/ Gunparts is the biggest parts place (next biggest is Sarco), so on their site, I think if you punch in your model # it will automatically cross-refernce it. Thanks.

Took time to answer your initial question, and a follow-up, for which I get nothing, and you leave negative/neutral feedback. Thanks.