This particular model was news to me. I had a 60's Super 20 Symphony "Harry James" model with a totally different valve block design. This looks closer to a Silver Flair valve block. I had heard that he had King special make his horns with the "balance" valve forward design used in the old Selmers and Olds Recording but had never seen a picture of that design in the Kings.
http://www.usd.edu/smm/HarryJamestrumpet.html
Hope you all find this interesting.
Andy