Steamwolf those look great! I really like those maroon swinging pilot assemblies.
EDIT EDIT EDIT EDIT.....I didn't realize the units you were showing were from Unique Art, I just assumed they were Marx because I ddin't know any better. My comments below were based on that assumption. END OF EDIT.
I bought a Santa Fe version a year or so ago with intent to repower it. It's one of many projects I may never get around to.
I am super impressed by the lithography on these F units. I wonder though is the swinging pilot just how the Rock Island units came, or is that an extremely well done modification?
Congrats on a beautiful acquisition.