The pic isn't the best, but I can't see anything stamped over anything, and the Broad Arrow stands out proud. Was it not the practice to strike out "Government" indications as a rifle was deemed surplus and relegated to "Commercial" usage? (Broad Arrow struck through)
Yes, it is a fuzzy pic, but I can definitely see that date code mark stamped over the top left hand corner of the 18.
As I understand (and I too am fuzzy on this) some martial proof marks were struck through in the flint muzzle loader days when arms were surplussed, but am not sure as to how widespread was the practice.
Arms with multiple Govt markings help tell their story. It is common to find early Lee Enfields with British War Department WD broad arrow mark, Canadian C broad arrow and New Zealand NZ broad arrow markings.
The double broad arrow is an example of cancelling a government property stamp. However, the double opposing broad arrow head 'Sold out of Service' marking has caused some recent debate. Perhaps it's use has changed over the years, but I am of the belief that it's use was not a sold out of service mark when it was retired from Govt use and surplused to the public through dealers.
I am making efforts at researching this, but certainly in the area of my collecting interest (late 1800s) I have reason to believe it was used as a 'Sold out of
British stores' marking when sold to another government where an arm would be used in service wearing its double broad arrows.
Let me add that if an arm was sold and shipped to another govt directly from the factory, it would not have the double arrows as it never was in British stores inventory.
But perhaps that should be saved for another thread?