Sorry I didn't get to you sooner patreek, it has been a hectic week. It's not a bad upgrade, the turret is pretty good. I haven't seen the ICS reference image so I don't have much to go on, but the rod holding up the crows nest seems to narrow. It looks like one little shot or guest of wind would topple it. Maybe there is a way of encasing the latter in a second piece of tubbing, making it look a little more sturdy and like it provides some more protection to whomever is climbing it?
I think what throws me a little is the scale of it. Not that you could have gone any smaller and still fit a figure inside of either the turret or the crow's nest. I'm just not a fan of the Hasbro toy itself. I think you should consider repainting the entire tank. Most of Hasbro's recent vehicles are WAY to clean looking it needs a slight wash, it really doesn't need to even look dirty, but it needs some sort of wash to highlight the paneling and the rivets and whatnot.
It's a pretty good start though.