I guessed at the shotgun but others had already guessed the same and were incorrect. I had guessed Stephen Grant.

Sorry Dave, although similar to a Grant, it is not. The exclusive vine & scroll engraving style of this particular maker tells the tale.

Scott? Greener? Richards?

None of those, Mike. Seems like you might be taking the shotgun approach with your guesses. Better use the rifle approach and zero in on the house engraving-style of this London maker.