Copyright of real-world military vehicles in commercial games?

Hi, I know this may not be the best place to ask question for legal advice but I just want to get a general opinion

I am working on a model of a tank that I plan to use on my game but I am a little reluctant as I am aware that some games acquire legal permission (what ever that is called XD I am not familiar with it) to use modern day vehicles. As for me I am planning to use a very old model of a tank and I am wondering if it is still suffer copyright issues.
The vehicle I am planning to use is a Skoda PA II “turtle”