HO Scale
There is a company producing die-cast HO models of CAT's tier 4 SD70. they're not functional, but very nice to look at.
they show the locos around the 1:20 mark
youtu.be/ahHUcbJYi1k?t=1m22s
If you're thinking about ordering one, they're backordering right now, they'll be out in august. once...