Sounds like a great day and I'm sure one that will be remembered. I hope you took lots of pictures.
That Noon Mark Diner in Keene Valley sounds very like the one on the Lake Placid tri bike route I used to pass. There was one on the way to Elizabethtown that I stopped at one time on the way back to the North Pole campground too, and I can't remember which it is. I sure did enjoy that summer in Wilmington, and that whole area.