I know there were a bunch of grey market vehicles imported in the 80's. But none of that testing/approval carries forward to newer G-wagens. That Short Wheelbase G-wagen cabriolet is a 2005 and is much different than what was sold in the 80's. NO SWB G-wagens were originally sold in the US. However, it is on the non-conforming eligible list. I've seen one in L.A. driving around.
View attachment 1843884
They likely went before the bureaucratic Gods and allowed the ceremonial attorneys to sacrifice hundreds of forms arguing similarity. It is, after all, still a 463 chassis G wagon that likely uses engines set up exactly like ones that were offered in the US.