A capital "B" is believed to be the British inspector's marking which is located on ALL Savage No4 rifles.
Your rifle is not and was not a Long Branch, nor was it ever at Long Branch.
Early BSA manufactured No4 rifles were similarly marked with a capital "B" (before the M47 code was adopted), does that make them Long Branch rifles?
I see you edited out your snide remarks before I had a chance to respond. If my original post offends you that much why bother responding? I will remove the OP if I have ofended your highness. Sorry for asking a question.