That is a jewell!! My wishful thinking was MS 65 but I can see MS 66 all day long. Is that the finest known?
I have both the type A and B in both PF and MS Silver strikes. I call them "peg leg" varieties. I believe some leftover proof dies were used on some of the silvers. I'm on the road now and on my way to the Denver Show and will ask some experts about these while there. I believe both varieties are common.