BRASS HMV back-brackets?

[Steve]

I'm just curious if anyone else has ever encountered a brass HMV back-bracket? I have now seen what appears to be a completely genuine back-bracket with nickel plating identical in age / patina to its accompanying tone-arm but where the nickel has slightly worn (on top edges and high spots) it appears it is brass underneath! The whole unit is much lighter, perhaps unsurprisingly and much cruder in form but it does not look anything like a repro. Any ideas? It also has a serial number stamped into the back flange where it bolts to the cabinet. This I have never seen on any other.