Difficult to say, the font is similar to Simpsons and I had one of their Persian jar shape handles which had the lines similar to that. My Rooney has similar but is stamped Rooney. I would say it's a Simpson and the label came off. Do I win a prize?
You mentioning the Vulfix it does remind me of the Vulfix 849I agree the handle is celluloid otherwise known as French Ivory and is probably an unbranded brush made for another retailer. My guess would be that it isn't a Simpson for a couple of reasons... the lamp blacking is tidy and I don't believe Simpson have ever used such a numbering system but Vulfix have and do.
I thought sterilised can be spelt either way in which case I prefer the English or British version.