Most all of them are Westbrook. All of them are ancient by today's standards. They spent several decades wrapped in newsaper under various layouts my dad had since 1996, and before that they were who knows where. All are wood construction. The Westbrook cars have cardstock overlay sides. They have gotten a bit beat up over the years, and I have repainted most of them. I used the worst of them as a paint sample car and am pleased with how well the detail of the card stock shows through the new paint. They decal easy too. I'm sure some Westbrook collector out there just blew his stack, but rest assured, I don't refinish antiques unless they are truely beyond help as far as a slight touch up goes.
I am using Lionel SP caboose frames trimmed to fit, and am trimming back the center beams as well as removing any scale details in the wheel area that would interfere with truck mounting and operation. The flat frames are the way to go and give the most realistic height.
So far I have preserved and only converted an L&N flat car, and have refinished 3 boxcars into Southern, DT&I and C&EI. I like midwestern roads. I have also done a CCC&StL hopper of unknown manufacture. The flat car came to me with a copper pipe mounted on it. It tracks excelently with Lionel postwar trucks and weigh's a ton!
Eventually, I will restore the PRR X31 boxcar and a 50 foot auto boxcar. These sides are wood, and not card overlay. There is a lot to do on those.
I am only using salvaged PW Lionel parts for the conversion process. It is what would have been availible back then if this project was being done in the 1940's or 50's. The staple-truck is preferred since that is most in keeping with the production era of the rolling stock.