Madison Hardware did make those diners, they made them during WW2. They needed stock to sell. I have one on my layout, They also produced a bunch of tank cars in the 60's. n 1962 or 63 Lionel did a run of 6572 Railway Express Reefers. They are light green. Madison also took 6468 New Haven boxcars and put brown doors on them and sold them well into the 1970's.
Regarding the book, A Madison Hardware Story, I wrote a chapter along with a few other formites...