I noticed that the PRR had a good number of outside braced boxcars like this one. 
I was wondering if any of them would be lettered for the automobile service like this one on the UP 
or this one on the PRR. 
They did have steel side auto box cars, but never saw OS braced wood ones.
Maybe back when Ford was making Model A cars since there was no other mode of transporting autos over long distance.
That would be my wild guess.
Alex:
Pretty sure the PRR car in your photo is an Accurail car. Not quite an exact copy of a PRR X26 USRA single sheathed car, but not too far off, visually. These were all single-door cars. They may have been used for auto parts loading, but not for the completed autos.
PRR’s wood sided cars were pretty consistently double-sheathed until about 1911 or so. Those cars had vertical siding and no visible outside braces. Around 1911, PRR introduced the X23 boxcar and the X24 auto car. These were the first PRR mass-produced outside braced cars, and they introduced a unique PRR outside frame with very heavy-duty pressed steel outside frame members. The best HO kit ever produced for these cars is the Westerfield kit. The X23’s were typical single-door boxcars, and the X24’s were somewhat taller door-and-a-half auto cars. R7 refrigerators used the same framing as the X23. After the X23’s and X24’s were introduced, the PRR went to the all-steel X25. Then about 1918 they accepted the USRA X26 because of the demands of the USRA in WWI. All later PRR boxcars and auto cars were steel.
The X24’s were deemed too low by about 1930, and the PRR began to buy round roof steel auto cars (like Bowser’s) which had a higher inside height. Many X24’s had their half door eliminated to become straight single-door boxcars, and many X24’s were converted to K7a stock cars. A few X24’s may have lasted in their original configuration into the early 1950’s.
If you want a PRR auto car, the easiest way to get it is with a Bowser double-door round-roof boxcar kit. By the way, Bowser also sells a stock car version of the round-roof cars. These were conversions carried out around 1959.
Tom
Thank you all for the info.
A link to a diagram and picture of the X24: http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=x24.gif&sel=box&sz=sm&fr
