@Krieghund:
Yes, you can have more than one AA gun in a territory in Revised, and you couldn’t in Classic. However, in Revised only one AA gun per territory can fire during the same turn, so it generally doesn’t do you any good to have more than one.
The only time having more than one AA gun in a territory can benefit you is if they belong to different countries and both countries have Rockets. That would allow each country to fire Rockets out of that territory on their own turn.
Short of keeping some sort of paper record, how would you differentiate between the two AA guns for Rocket use? I had assumed that with the neutral color, two countries could not have AA guns in the same country. If this is the case, then the US and the UK having Rockets could prove to be a big headache for the Germans in both Revised and Anniversary. Combine that with Strategic Bombing Raids, and Germany might not be building a whole lot. Four D6 rolls should average out at 14.