Hi - I just posted an image of an extremely tarnished hallmark - i’ve attached it again to this post. The initials on the left may be W.G.S Ltd I think, but not sure if it’s a “w” or not.
It’s a lid to a 1920s-30s powder box. I’ve assumed it’s silver but when I tried to clean, gently with some white spirit even though the black comes away there doesn’t seem to be any silver coming through so I’m wondering if it’s plated and all the sliver has been polished away.
Any help would be very appreciated1
This is a completely valid and correct silver hallmark. The lion passant guarantees sterling standard (.925) and the rest of the mark indicates the Birmingham Assay Office and date letter M for the assay year 1936/37. The maker’s/sponsor’s mark is, as you thought, WGSLtd. This is the mark of W G Sothers Ltd.
White spirit is not a good cleaner for silver - it won’t do any harm, but it won’t do the required job either. You should try a good quality silver polish of a non-abrasive nature, but the tarnish looks really heavy so it will take quite a lot of work.
Phil
Hi Phil - Thanks so much for the info, much appreciated 
Will try and polish using a proprietary silver polish as you advise.
