Clint,
The temptation to use rust heavily with armored vehicles is always a strong one but it's something that can be overdone depending on the circumstances you're looking to depict. Considering that this vehicle was in-service and not a wreck, I would suggest replacing rust as a weathering approach with a darker color like burnt umber for dirt/streaking or chipping effects. At a minimum I would suggest toning down the rust effect you have on the spare track run, in the lighting you have for the photos it appears very orange.
The last pic also seems to show that your barrel ends on the Flakvierling aren't painted but you may already be aware of that from you comment about paint chipping off.
Overall it looks good, can see a progression in your technique for sure!