I should have mentioned I went to Rutgers, back when the "original" grease trucks were there - parked up and down College Ave. Not located in a converted parking lot.
Grease trucks - Wikipedia
en.wikipedia.org
This was before the advent of the "Fat" sandwich. Fat Cats were always around (Cheeseburger with fries on it) but things like the Fat Darrell were not yet a thing. You could just add stuff however you wanted. A Cheesesteak Hoagie (A cheesesteak with the addition of lettuce, tomato, and raw onion) was already a thing. One night it just felt right to add to fried egg to it. "Cheesesteak Hoagie with Double Fried Egg" came out and it was a thing of beauty.
I ate them on a almost weekly basis for the next two years. Never though to call it a Fat Dave
Cheesesteak hoagies are my go to cheesesteaks. My order is always lettuce, tomato, ketchup, and mayo. Now I gotta add some fried eggs!