The only book I'm aware of is titled "Rails Across Delmarva" by somesuch somebody, and published in 19 diggity two. We had a copy in the Maryland Room of our local Cambridge library, but someone kiped it... before I had a chance to!
I saw a copy in a used book store in downtown Ocean City last May, and they wanted $60 or so for it. It is out of print, to be sure.
It seems to me there was a Morning Sun book announced recently that was to include some information on the subject, but I can't recall the details.
Lee