I've sent some pics to Richard Gallyon and awaiting his reply, I had spoken to him before buying the gun he had records from 1912 but thought since the serial number was 218 it had to be older.
That has got me thinking about the age also, it's very nice shape, do they put black powder proof marks on guns that are newer, this has both BP and NP Proof marks and yes the V view mark indicates London, I didn't know that also meant that was where the gun was proofed, could it been made in Birmingham where the barrel marks came from and BP proofed, then sent back to London sometime later for NP Proo