Strange, but in testing what happens when ships are sent back for upgrades, the CV Lexingtion came back WORSE on the second trip then it started with originally. This has got to be a bug, because it simply doesn't make any sense that the AA upgrade would actually downgrade the ships weapons.
First trip is nice, with junk being replaced with lots of 20mm and 40mm guns.
Second trip sees a bunch of the 40mm removed and a few 20mm added.
Net result:
AA value of 2078 -> 2208 -> 1948
