(Edited to update photo links)
Lou Houlemarde, current proprietor of Central Locomotive Works, did a run of Baldwin Transfer Locomotives two or three years ago. Both the DT6-6-2000 and RT624 were offered. It was my impression that the same chassis was used for each. As I understand it, Russ Briggs or some other non-CLW modeler did the artwork needed to make the brass etchings for the RT624 version. The modelers are an improved version of Bob Smith's "wrapper" version, which I believe was his last run of models in the late 1990s. The new version has a redesigned chassis (like most of Lou's more recent offerings) as well as a Jay Criswell drive. The model is very, very nice.
I have been posting my own four-axle diesel doorstops in the order in which they arrived. Here is another set from the summer of 2011:
https://dl.dropbox.com/scl/fi/wvul8gp8edpv65ij5uz2s/Jack-Collier-EMC-FT-AB-Set.JPG?rlkey=7gfeec1gochnin5iczkifa9hbIgnore that "F3" mark penciled on the cab - These are FTs. In particular, these are Santa Fe FTs, as indicated by the fifth porthole in the B-unit. Most FTs came with drawbars between the A and B, but the Santa Fe insisted on couplers. The extra porthole is for a hostler's station, so the B could be moved independently.
I made all sorts of guesses over the years as to the origin of these but have found nothing definite. John Fisher, however, sent me a copy of an "Old and Rare" column he wrote for O-Scale News in which he posted a photo of a similar unit and asked if anybody could identify it. Somebody wrote in to say it was a Jack Collier model. Jack was proprietor of an Oakland (and later San Francisco) hobby shop, known by its motto, "Toys for Men". To the extent that Jack is remembered today, it would most likely be for the GG1 he offered. There is one piece of evidence that indicates that Jack Collier might have indeed been in the cast model business, and that is an Adams and Son advertisement that lists Jack Collier as a customer.
Jim
(Edited to correct Lou Houlemarde's name)