RE: Question regarding a book
Ohh come on Bill, you've forgotton more then I'll ever know about tanks!
My best sources of information on the Tiger I have been the books by Jentz/Doyle/Sarson and Restayn. Also have one of those Russian books that has excellent photographs and diagrams of all the detailed changes made. I'm sure it says great things too but I don't read Rooskie!! There's also a chinese website called Legend of the Tiger that google translates.
7xx series tanks were from the 501st. The 504 tanks, there were only 8 supposedly were numbered 111, 112, 121, 122, 131, 132, 141, 142. Small red numbers and also had a unit insignia on the sides, some on the front. I think only one other 1 Kompanie tank had the foot support on the front of the tank like the 131. You'll see this in the book by Restayn. When the 501 tanks were absorbed into the 10th Panzer they put their unit insignia on the glacis plate above the drivers visor. You don't see that on tanks with the original numbers.
I really enjoy doing the research. I want to depict at least a couple of my Tigers as accurately as possible. It's my pleasure to share the information!