It looks really nice. I always appreciate when someone does a decent rendition of this world changing tank. IMHO it was so innovative it really needs a better representation in the RC world.
The casting work looks really good as well. I put bearings in mine as well as the stock versions eat themselves up pretty quickly. I also had good luck filling the suspension arms with milliput to sure them up. Gearbox swap is a must but you already mentioned that.

Once again, nice job.
Perry