Technically, I'm already using Paul's turrets, the only difference is that I still have the gun barrels at 6-pixel thick instead of 7 (not even the 18-inch guns from Furious and Yamato are drawn that thick)
Anyway Colo, according to the HNSA's Turret Catalogue you linked, the 16"/50 you have on the BB-61/63 drawings are closer to the measurements given there than Paul's one, does the HNSA provided two different measurements for the Iowa's guns?
50 feet, 7.5 inches in length, 120 inches in height, barrel protruding ahead of the turret face (lower fowardmost spot) by 42 feet and 4.5 inches.
It translates into 101.26 x 20 pixels + 84.75 of forward barrel lenght (If I've not screwed up).
I suddenly feel nitpicky as I've never ever been before