Identifying an Original Enfield Bayonet

[Murph]

Pardon me if this isn't the right section to put this in, but to get to the point, I have in my possession an original Enfield-type bayonet that has a heavily worn stamp on the interior of the blade, just above the shoulder of the shaft. I've used the magic of the internet to 100% conclude that it once read "W. Higgins & Sons," as well as a stamp bearing a crown and the characters "B 57." On the shoulder, there is an inverted number "4" stamped below the name of the maker.
I would love to know the provenance of this bayonet, whether it was possibly an imported weapon, or a post-war make. Short of a few online auctions that offer little more information that what I have already shared, I can find no information on this piece. Anyone have a clue?

I've attached an image of a similar bayonet found on a popular auction website; Note that this is not my bayonet:

[Craig L Barry]

Re: Identifying an Original Enfield Bayonet

I believe that is a Birmingham contractor made bayonet for RSAF.
W Higgins and Sons were suppliers to the War Department during the 1850s.
Usually crown over the capital letter with numbers beneath it are British Army.
E = Enfield, B = Birmingham, S= Solingen, F = France, L = Liege, etc.

According to The Mechanics Magazine, Vol XXXIII, (1855) "Messrs. W. Higgins and Son, of Salford,
are also engaged in casting shells, and particularly Shrapnell shells of a new and improved
construction, for the Ordnance Department." Salford is in NW England near Manchester.

[Murph]

Re: Identifying an Original Enfield Bayonet

That's just the sort of information I wanted to know, Craig. Many thanks for the very insightful reply!