Unknown Maker's Mark

I am an avid collector of Vintage Costume Jewellery & have been collecting for over 12 years. I had recently acquired a lovely set with all pieces (both brooch & earrings) marked with a maker's mark I am unfamiliar with. It looks as though it is a capital letter 'B' within a 'Shield / Crest'. I have spent many hours / days researching & have had no luck whatsoever in finding the least of information for this particular maker & their mark. The set is in excellent condition. No flaws to the blue glass cabochons.
I hope someone may be of further assistance in possibly being able to identify the marks.
Thankyou.