Thank you all for your support.
Tim, no offense taken indeed. It's a perfect observation about the build; its whole concept. I built this gun with my great friend in mind, so every aspect of it had him in my mind. I had no idea of the hours swimming past as I worked away on little details. I took pictures along the way and sent them off to him at the end of every day, or part of a build. His responses were always reassuring. An example occurred right at the end of the build, when I case hardened the engraved screws, then burnished them in a soft wire wheel. The result was a dramatic change in their colour and texture, from mirror polish to subdued black/grey. When he saw the result, he commented that he didn't like the appearance of those huge screw heads on the side plate in Chambers' web site example, but really liked the look of them on his gun.
We spoke yesterday on the phone, and he plans to come north when the weather improves, to shoot it and take it home. I will be test firing it first of course to make sure everything is working as it should, and to file down the rifle front sight to get it into the black.
I really enjoy shooting my own PA fowler with ball, and there's no reason this one should be less fun. The stock has just the right drop and lop to make it most comfortable and accurate. With my own gun, I have 'aced' several trails in competitive shooting, and my buddy Norm shoots his (also a lefty) like a rifle. Great design.