Hello JackieF, not sure whether you wanted values or info on them, as I’d seen most of these actual plates listed on eBay a few weeks back.
My 2p’s worth is that out of those pictured it’s only the Sydenham that’s the uncommon one, the others pop up quite often. It’s more likely off a badge engineered safe made by one of the Black Country makers to bear the dealers name.
It says Merchant and Manufacturer on the plate but the Manufacturer bit wouldn’t necessarily have to mean safes.