May I know more where I could find the rules for the 39 historical edition? I opened the map and it seems there are few more units inside. I am thinking of having the map printed and give that a try :)…
Sankt is correct. The SUB may still chose to leave the SZ in COMBAT movement phase of their upcoming turn. However, if the SUB does not combat mvoe out, then Comabt will occur with the new fleet.
Under LHTR, in the description of AA guns, it does include a specific exception to AA guns ONLY moving in NCM when being carried on TRNs.
It is not 100% conclusive. But it is more than enough to make me think that the AA gun does indeed offload in COMBAT movement (but of course cannot “attack” so it is ignored as a unit for the attacker). If the Attacker wins the combat, they finish setting up the AA gun in NCM, and it protects the newly captured territory. If the attacker is thrown back into the sea, the defender gains the AA gun.