Help needed on Hallmark on Silver Plate Entree Dish

I was left an EPNS A1entree dish which has the hallmark B&W, I think (see attachment). I thought it was Burton & Waters of Birmingham, UK, but they used plain lettering in a lozenge. There are also numbers scratched into the surface, which are no evident on the attachment. These are K3505 and U/U/-. Can anyone help me with where this was made and by whom?

Thank you in anticipation.

silverfox
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