Unfortunately, it's never been done in 1/25 except by brave modelers. One I've seen was done using the 3406 engine from the Revell snap kits and some AMT Cummins parts. It looked fairly convincing. I've wanted to do that and the 1674 as well. Finding reference material on them isn't easy, but I do have pix of a 1693 in a 1972/73 KW W900 if you would like to have them. Let me know.