OK, so I've had my trading post thing up there for quite a while, and have managed now to snag a baggage/RPO car, two coaches, and I have my original "Mayflower" observation that goes back to about 1979.
For somebody that hasn't been in N scale since the 1970's, these are a classic, yet primitive kit. Brass etchings, some wire, maybe some window material, some wood shapes including a roof. Next best thing to scratchbuilding. The redeeming part is that they made stuff that NOBODY else did,the line of early 1900's vestibule passenger cars with truss rods, wood sided; lots and lots of interurban trolley cars, and a line of structures. The brass etchings are really good, the rest, well..... I'm not sure what "Programmed Construction" means, lost when you look at the instructions. They were competing with Quality Craft, and those kits were far superior at the time.
I did the "Mayflower" open-end observation as a private car as a contest model back in 1979, took an NMRA award with it as I did full interior detail down to silverware on the table. Really just a throwdown to the HO guys, I'll admit.
Since then I've been building a circus train tribute to J. Augustus Jones, Cole Bros. circus owner, lived just down the street from me, tragically killed by a horse kick in his own train. The train is locked in to the date 1917. There are photos of him with the train in "The Circus moved by Rail" (Carstens). They also have that epic advertising car of his in the book that looks exactly like the Western Railcraft RPO.
Circus passenger cars were notoriously obsolete, and in the photo is shows vestibule-end, wood sided, truss-rod cars. The only thing even close in N scale are the Western Railcraft kits. I'm doing a train so far of 2-3 stock cars, 7-8 flats, and 4-5 passenger cars, which agrees with the detailed car-by-car train list published in "Billboard" that year. And Jones had his own private car on the end with his family in it.
I'd come to the conclusion in '79 the only thing worth saving was the sides and ends. I'd hacked up Lima standard cars to get bolsters, underbody detail, end frames, and clerestory roof. The middle of the frame had to be scratchbuilt to size from styrene and stripwood, and the roof insert shortened to fit the sides. So the 'new' builds took the same approach, including adding MT 6-wheel passenger trucks with a redrilled bolster hole. Truss rods were brass .020 kingpins and soldered .010 brass wire. End steps are from scrapped-out Kato caboose frames that have gone on to be pickup cars and tenders floors.
According to "Billboard", the wood coaches were painted in "A pleasing C&O color scheme", which a little research discovered was orange with red trim in that era, and it could only be that colorful if done over white primer, so the brass sides are primed. Custom decals were made for "Cole Bros. World Toured Circus".
While there are few photos and no color of the train, it's amazing to have such a detailed written description of the circus to work from:
https://books.google.com/books?id=XaoiAQAAMAAJ&pg=PA72&dq=Cole+Bros+circus+Jones&hl=en&sa=X&ved=0ahUKEwi6--Hi47ThAhVNeawKHQ6qC88Q6AEIQjAF#v=onepage&q=Cole%20Bros%20circus%20Jones&f=falsePartially finished second coach showing construction:

link:
http://www.randgust.com/Western%20Railcraft%20603%20rebuild%201.jpgFinished first coach:

Link:
http://www.randgust.com/Western%20Railcraft%20603%20finished%20car%201.jpgSo if you do see another one of these old dust-covered beauties, I could probably use one more car, or I may chop up an Overland car set like Mark Peterson did, the hard way. Too bad Shapeways isn't still alive as that rendering would make a nice print.
The amazing life story of Jones has been a passion of mine, after some Historical Society presentations the local paper wrote a story on him from the material I collected. The credit he doesn't get, that I suspect, but can't prove, was the original designer of the steel "Warren" circus flatcar, as it's in the town, he was having trouble with wood cars, and his bank financed all the cars for circuses.
https://www.timesobserver.com/news/community/2019/05/kings-demise/If you go to the Circus World Museum in Baraboo, WI, the Warren flatcars still have the trust plates on them for the Warren Savings Bank, Warren, PA, which is directly across from my office; that was his bank.