I am related to the William Marshall of the Marshall Cabin. He did not come from Scotland, however, so I think you're both referring to different people. "My" William MARSHALL (1826-1930) married Mary Jane CLAFLIN in January of 1847, and the couple bore no children. William was the son of Van Rensselar and Phoebe (EATON) MARSHALL, both of whom are a brick wall in my research. I am a direct descendant of their daughter and William's sister, Lydia.
I have additional info on William Marshall and his cabin and would love to learn what you know. If you're on Ancestry, you may send me a private message. Otherwise, you may contact me at lady_guinevere(at)vegemail.com.