How to limit the number of items

I’ve made some armor upgrades for the next update and I’m searching for a way to restrict the number of how many armors can be hold on one char.
U can only mount on of the armors, that was easy but limiting the number of unmounted armors is not so easy.
First i though of doing it by cargo space, but that would mean that a frighter or battelship could hold lots of em.

Has anyone a idea how this can be done?

Ty in advance for your help
Mindhunter