I'm not talking about a tank that runs and functions as-is without any helping, nor a tank that can perform in it's original capacity.

More along the lines of a chassis- a framework, perhaps.

But failing that, I hadn't realized Eden was fond of restoring old tech. If that's the case then perhaps this character could be somehow integrated in there, given a common interest? 

I'll admit this plainly; I'm straining for a tank here, (because why the hell not?) so however I can reach that goal is fine by me. What should I look into?