There were a series of posts on Walthers and JC heavyweight passenger car kits under the Atwater/All Nation locomotive thread and I thought folks new to O scale 2 rail might be interested in learning about some of the fine older models that can be found at O scale shows and swap meets.
As far as heavyweight passenger cars kits, in my opinion the highest standard was set by Ralph Brown's American Standard Car Company. His side rivet detail, belt rail, window sash representations were orders of magnitude better than the stamped steel sides by Walthers or JC. As best as I can tell from my incomplete collection of old ASC catalogs, Ralph designed and produced kits for at least 56 different prototypes. He also produced a wide selection of streamline car kits in O scale under the American Lightweight Car Company brand. Due to health issues the ASC line was sold to an individual in Knoxville TN who intended to continue production under the Pullman Scale Car Manufacturing Co. brand. PSCMC Catalog 1 dated 1995 listed 59 kits including 3 one piece resin body kits. While I've seen hundreds of ASC kits and built up models at O scale show, I've not seen a PSCMC kit. Attempts by a friend to order catalogs, kits and parts from the PSCMC's Knoxville P.O. box address were unsuccessful. Below are three examples of built up ASC kits -
The first is a PRR M70 RPO. The one piece sides are cast in urethane, the floor and roof are wood. Trucks are PRR prototype from PSC.
Below is an ASC PRR P70 air conditioned coach built by Ted Stepek. The kit came with a urethane roof and sides and rides on Walthers trucks. Back in the 1980's correct curved PRR passenger car steps were not yet available so it was offered using Walthers castings. Some day when I may replace the steps and trucks with brass ones from PSC. Meanwhile I enjoy running it as is.
Next up is ASC's very nice model of a Pullman plan 3992 13 chair parlor buffet lounge. It is interesting to note that Ralph Brown used prototype Pullman floor plan numbers for his ASC kit numbers. ASC and the later PCMC catalogs featured drawings of the car sides and interior seating/partition arrangements. Most kits were available in as built non-air configuration, or with air duct and related underbody details for the air conditioning upgrades applied to many heavyweights starting in the mid-1930's. Most Pullman built parlor cars had clearstory roof decks that were wider than used on sleeping cars. AC roof ducts retrofitted to the parlor cars had steeper and sharply angled contours, making the cars easier to identify in old films/videos. 
