Hi Bruce, that is interesting and reassuring!
Once bought a Deans product and was not entirely satisfied. Sounds as if this will be better, wil know in about a week when it arrives.
I could not find a kit for the 4.5" Cannon fitted to some Darks. Do not confuse with the usual 4.5" gun fitted to larger vessels. Very different.
RN in Munich sent some scans and am working on it. Not difficult if you break it down into sections. Am making it from bits of scrap so appeals to my Yorkshire Heritage!
Assume you are building a 1: 24 Dark, where did you get your hull or are you building from scratch?
I have ordered one from MTBHulls but think they are closed due to a lock-down.