Good find Warren! But, what about the possibility that's it's a Lingham plaque that was fitted on one of the commonest, most generic and non-descript Black Country safes because it'd lost its original one...

That style of safe could pass with any one of dozens of different names on it.
Even Cartwight's and S. Withers' bottom of the range offerings looked pretty much the same, hinges, handles etc. You'll see those shield escutcheons plain, also marked Patent, Invoiable Lock etc.

Only kidding though I'm sure Tom's comments above are correct and it is an example of one, albeit an obscure name from the very bottom end of the market.