The closest I've come to a genset is GP20D I worked on a few years ago. It was designed to fit over the AZL GP30 chassis. I stopped work on it because the chassis of the GP30 was just a bit too tall and I wasn't brave enough to start cutting it up. I liked these locos because I would see them around the Houston industrial areas running on UP tracks. I like those big windows.
Rudy, the 44 Ton'r would be a great addition to ‘What’s available in Z scale?" that we do at the National Train Show, using the "BFY" (Big F'n Yard). Here is a pix from setup. when we run, it's FULL of all the MTL, AZL and others. Next show is in Santa Clara ~July 2021. Should be enough time