I wonder if those Deses F units you have are repaints - all the models I've seen have the original olive green with orange striped EMD paint scheme with Deses logos at the back of the shell. I have 2 pair of the original paint scheme in green and orange with the railroad name spelled out (the picture on the factory boxes looks suspiciously like the EMD paintings on promo cards I've seen).
I spent years trying to find a pair after running across that article in O Scale Railroading around 25 years ago - Ebay yielded my 2 pair, including one set from Sal Olsen that didn't have their boxes. About a year after I'd purchased them a box arrived from Sal with a note saying he'd run across some boxes for the engines I'd purchased and forwarded them to me. Those boxes had a Sears price tag on them - must have been a local buyer for the Cleveland area Sears stores giving Deses a shot. I also missed out on a lone gray paint version model on Ebay - that also had the Deses logo on the rear portion of the shell. I've never seen a Santa Fe painted model from Deses - seems odd given the popularity of that Warbonnet paint scheme, especially in the U.S. 3 of the boxes I have are marked olive/verde, the 4th is labeled alumino - that one came from Mr Olsen.
Like yours, there's some bowing on one of the shells I have, some missing steps and some zinc pest (Dorfan's Disease) has done some damage around the trucks. The mechanism is neat to watch with the shell off - the Flyer reverse unit does the job, and performing maintenance is easy.
My favorite Deses moment came years ago when I was a runner at Greg Stout's auctions that were held at the Armory building in Indianapolis. I took a pair along for show and tell before one of the auctions - no one had ever seen them before (and they were shown off to the high rollers and long time collectors). No one had a clue what they were looking at.
