David,
Congrats on a sublime revolver!
I remember when we spoke about this revolver and I asked what the rear sight configuration was. I'm not at all surprised to see the U groove style blade. I'm crossing my fingers that the gun will letter as having shipped in the configuration you have it, but in any event, it will be interesting to learn what details unfold from Roy's letter.
I'm very happy for you that this gem went to you. You might want to be careful though, good old GLL might stalk you for that one.
Best,
Michael