I am an avid history buff, and I have occasionally built models. I'm generally not really into military-related stuff of any kind, unless it's from pre-modern periods. But if I did find the design of a particular plane, ship, etc. used by Nazi Germany to be interesting, and I really wanted to build it, I would leave off any identifying marking/symbols. I probably wouldn't build such a model in the first place, though. I find it somewhat problematic to try to separate the purely technical aspects from the regime that used the equipment. Looking at the same period of international conflicts, I have living relatives who experienced life as second-class citizens under the Empire of Japan's sphere of influence. Any memorabilia, models, or whatever having to do with the Imperial Japanese Army or Navy just hit too close to home for me, and I could never have such stuff in my home.
Kor