You have a very nice piece. The figural items will always be of interest to collectors. The market is very finicky right now but there are still some nice prices on pieces - and with the theme of your piece you will have people interested. I would be interested to see if this ends up being an Alfred Mayer piece from the late 1890's to early 1900's.
You never stated the size of your piece, that is important. Also, the weight of the piece.
I wouldn't say that WMFB pieces are RARE. But your piece appears to be in good shape (from what I see in the pictures) and no damage.
Brittannia Metal is pewter-type alloy. However, the letters i/o indicate that a silver component is added to this piece as well.
I believe that you getting in touch with the auction houses is a great idea. You will at least see if they have an interest in it. They will need the measurements of the piece and weights as well.
Please let us know what you hear back!