Anchor symbol on British 121/124 fuze and Kynoch cartridge cases?

[Darkman]

My friend Ron has been aware of an anchor symbol on some Kynoch cases for some time (look above the year on the pictured case.) He's not sure if this was something to do with Kynoch themselves (i.e. an inspection mark) or an affiliated repair contractor etc. Then he noticed the same anchor symbols on a 121 converted 124, 2 pdr fuze. The fuze was made by "GK" in 1917 (GK is George Kent) and converted by RL in 1923. So the fuze apparently has nothing to do with Kynoch that the other anchors have been associated with.
Does anyone know what the anchor symbol means?
Thanks, Graeme

 

[Darkman]

Any ideas?