Mr. Porterfield replied to my email! Much to my delight Mr. Porterfield said he would be happy to help me with my project, would give me written permission to use his printed recipes, and would provide me with some of his several thousand recipes he collected but had not been printed. Mr. Porterfield did ask me questions about the era of my story, the particular category of menu items my protagonist liked to cook and why he liked to cook.
After a couple weeks of thought I was able to answer Mr. Porterfield’s questions by providing a little family history of train travel and memories of the dining car. I thanked him for being my sounding board and told him I appreciated any advice he might have.