Weren't they used as naval guns, possibly on impressed freighters?.
These late COW Gun cases are interesting. I have two headstamp drawings only in my files.
1 1/2 Pr Mk1V Gun 1 RL. 1933. CF. Lot A. (I noted the Mk1V for some reason with a ?)
1 1/2 Pr Mk111 Gun 111. ICI 1942 Lot 3M.
seem to remember reading some where the COW gun was fitted to Sunderland flying boats for anti submarine. What we think would make sense in terms of 'new' gun production must be viewed from the start of WWII terms, what could they actually make and who needed it the most.