Jeff, give me a little time and I can be more precise, or maybe one of my freinds will chime in. In short, SVRy started shopping for new pass cars about 1914. They eventually recieved 2 idendticle 3 car sets from ACF in 1918. The cars sets were a coach, a passenger and baggage combine and a RPO. One car set was operated on most days all the way through each direction with crew and engines changes at Austin. When traffic was light, on the west bound, a coach was cut off at Sumpter. I don't know how often an entire 3 car train was run on the Prarrie end. As traffic dwindled in the 30's operations became more austere. SVRy at some point converted one of the coachs to a mail, baggage and pass. car. The last pass. trains had only the one car. The short car shown in the photos that have been posted is RPO #4. All of the cars were eventually transfered to MOW at SVRy after regular pass. service ceased in 1937. Pass. were carried in the cabooses of freights if there was a request. In the 40's there were two different sales of cars to the WP&Y. Actually the first sale was to the US Gov. for use on the WP&Y. I'd have to look up the car #'s as to which went when. Of the 6 cars 5 eventually ended up on the WP&Y. The one car remaining in Baker was RPO 4. It eventually became a dwelling. It was recovered by SVRR for preservation, but vandals or youths playing with matches set the car on fire and it was destroyed many years ago. The only thing remaining are the steel hoops that supported the roof and the builders plate. The RPO that went to the WP&Y was used in MOW but also was destroyed I believe in the 1980's. So there are 4 cars at the WP&Y that remain that started out life as SVRy cars. If you want dates and #'s I can put post them later tonight. I have noticed at least one vintage std. ga. pass. car now part of a restaurant in Eugene, Ore. that has a very similar roof design and the interior looks very much like these cars. On the exterier, the end of the roof on the std. ga. car is rounded laterally instead of being sort of chopped square.
Incidently SVRR has the negatives of the builders photos of these cars and in another colletion some of the materials from early on when the cars 25 and 26 were being quoted is extant. Pretty interesting stuff.