Question from newbie re. missing maker's mark

Hello all. New to this forum, love it, it’s so helpful to a newbie like me. I have a question I hope someone can help me with:

I thought that a maker/sponsor mark was a legal requirement on English silver… I have a sterling silver vesta/chatelaine case (it has no striker so it probably is not a vesta case) which I love. It’s heart shaped, heavily embossed and has clear hallmarks for Birmingham (anchor), sterling (lion passant), 1881 (g), and the Queen’s head duty mark. So far so good. However there is no maker’s mark on it anywhere. The piece is 40mm in width and weighs 14g.

I’ve seen 3 others of the same design on ebay, 2 were brass and one was described as gold plated. From the photos and from writing to the sellers/purchasers I have established that none of these 3 had any hallmarks of any kind.

So - do you think that mine might be the original from which the others were copied? Or, because of the lack of maker’s mark, do you think mine might be ‘dodgy’ and maybe ‘faked up’ from the more common brass ones?

I’d value any opinion on this little conundrum.

(I don’t actually mind what the answer is because I love the piece anyway and wear it as a pendant, I just want to know why there is no maker’s mark.) Thanks!