NdeM indeed used sg equipped GP-38's in the seventies on a lot of their premier long distance passenger trains, including the Aquila Azteca (Aztec Eagle) El Regiomontano, and El Fronterizo.
Opinion, they were GREAT looking units, however (per previous comments) this "Franken-diesel" version (btw great tag) is a little off from even that proto-type with the BS roof tanks, mis-matched trucks, and semi-SP-like light package on the nose. Fix those issues though, and you might have something if you're an NdeM buff like me, otherwise avoid if you're prototype oriented.