Unfortunately low resolution & small image
IF that is 1 1/8 to the R of the NITRO PROOF the marks would 1925-1954 with the (odd) chamber length
Probably just the terrible image but could there be sleeve lines at the arrows?
It looks suspiciously like the flats were polished and old proof marks removed?

[Linked Image from photos.smugmug.com]

Another WR from 1928 also with Westley Richards Special Steel (but a different mark) also with the proof marks on the barrels. Reproof marks are on the flats as expected

[Linked Image from photos.smugmug.com]

Maybe just a WR thing?