Mount Vernon Shops HO-scale FM decals
You can ask for the S-scale version of these decals.
Bill Lane's S-scale model
Shows the Funaro & Camerlengo kit built-up.
Bill Lane's O-scale model
Shows a LCL container-carrying model.
Fine Art Models 1:32 scale model
Large-scale models of brass construction, showing various loads.
Build a Pennsy Flatcar from Scratch
Model Railroader October 1977 article by John R. Porter, pg 81, showing how to scratch-build a PRR FM flat car.
Notes on how to build one in HO-scale