Yes thanks Novice, I knew that one of Colombo was there, I have used parts off it for some of the C & D units I have created, mainly the lifeboat stacks, Pepperpot radar, and the short mainmast arrangement.
I am still unhappy with it even as a real life unit. Imagine a new commander being drafted aboard Colombo in 1943, "You are going to a C class cruiser old man." "Oh good, which one?" "Colombo, just out of refit with six four inch" Dead quiet settles on the room... "It's got some nice new 40mm to play with." "When did it become an MTB?"
Even Colombo above could have had the 4th twin 4" aft by reducing the aft superstructure and moving it forward toward the pepperpot a few feet. Delete the five twin 20's in favour of another single/twin 40mm Hazemeyer mount. (But that's just me)..
By 1943, even in my weirdest moments, I would not be putting 'C's through an AA refit. I would keep the ones I had already done up to date, but the 450 odd crew aboard one with 6" would be more useful being drafted aboard a Colony or Dido while the remains become a Mulberry unit.