[:-] Ok, I really see only one problem, well two then... The amount of mass you have up top there is going to put a pretty good torque on that single screw if the new sight gets bumped - stripped barrel threads seem areal possibilty. I guess that was your thought with the o-ring?And you need to blue or alumi-black those sparkling jewels.

You had me on the edge of my seat...

With all that metal shaping, I would have to ask why you didn't build something utilizing that dovetail?