Stahl's tracks are stamped steel. I don't paint my tracks, I use a spray on graphite, coat all sides of the links & pads. That graphite sticks to the steel better than paint & is very lubricating too.
It seems odd to me that no one is more forth coming as to who actually makes this model or show what the inner workings look like.
Comparing the dimensions on RC4WD's site to Vario's JD450 machine, this excavator is just a bit smaller in stature. If the JD450 (12th scale) is considered to be a 40tonne machine, then this one might be comparable to a 30tonne.