Mark Rossiter asked:
"I am looking for an article that appeared in one of the modeling magazines back in the 1990’s that described replacing the stock fishbelly underframe on an Accurail single sheathed box car with a straight sill. I am aware of the Tim T. Swan article that appeared in the June 1997 issue of Model Railroading, but that is not the article I had in mind. A search using the TRAINS.COM magazine index was of no further help. I’m hoping someone on this list has more organized reference notes than I do."
Try John Nehrich's "Bettendorf Boxcar" from the August 1996 issue of Mainline Modeler, where he describes doing stand-in models for M-K-T and C&NW cars from the Accurail kits.
Mainline Modeler plays hell with the magazine index - one of Hundman's bad habits was using completely vague non-descriptive titles for articles.