prototypes?

[Paderborn]

Any chance of introducing prototype AFVs that never reached full production? Specifically I'm interested in the joint
U.S./W. German MBT development effort, which failed, that produced several prototype MBT/KPz-70s with each countries's version differing slightly from the other's. I think you have included some AFVs that never reached combat units such as the Russian "super MBT" whose name escapes me at the moment. Thanks!