Yeah, for a "good-enough" version, one of the MDC Pullman Palace cars would be a good choice.
If you wanted a more accurate version, I'd still start with the same car, but use only the roof and perhaps the ends, making new sides from Evergreen Passenger Car Siding. Grandt Line offers coach type windows - they're for narrow gauge cars, but should be useable for most of the ones needed.The real car had a steel underframe, which would be easy enough to replicate using the kit's floor and some sheet styrene:
Wayne
Nobody makes a model of the fish car which the Mid Continent Railway Museum had painstakingly restored at the Avelon rail rebuilder shops in Milwaukee. I was able to tour the car while the work was in progress. It might be that altered and shortened versions of some of the full length wood passenger cars that Model Die Casting sold years ago would make a basis for a "good enough" kitbash. I could send your husband a CD-R of my detail photos if they would be of any help (there are also many online photos). There is a message capability in the Forums for personal contact.
Dave Nelson
I am wondering if there is a model train maufacturer that makes this car. I have looked and looked and some help now would be greatly appreciated. My husband is thinking he will have to build his own.