Add the smoke stacks, and it IS steam...

I was surprised how small it looks for 15mm (18mm?) fellows. Add running gear, engines, fuel, ammo, and the insides must be the living heck I'd always heard.
Still, the example you dug up proves just how awesome it can be! Not so sure about the turret, though.

Concerning the IMP, I've cut the top off one set of tracks, and still plan on covering with a fender to make it look like a rather flat track return, of which my co-players approve, but I haven't liked anything I've thrashed upon for same fenders, nor figured how to do the firing positions on the now open sides.
As I've bought several on eBay recently, cracking I should get!
Well, someday...
Doug