1913 DWM.. Vickers proof marks?

[Vlim]

Indeed. The crown/V (and crown/P) are both markings that were (and are) used by the proof house in London. You will find them on all guns that went through the London proof house.

Foreign guns also usually received a 'NOTENGLISHMAKE' marking.

I have a Vickers that was actually reproofed in London and received, mistakingly, a 'NOTENGLISHMAKE' marking the second time. It was also reproofed which was unneccessary also, as it had already been proofed in the UK before.

Morale of the story: Proof houses also make mistakes. Plenty of them

The image shows some London proofs and the 'NOTENGLISMAKE' marking on a M1934 Mauser that went through London on it's way to Palestine after WW2.