Chas,
Sorry to go against the grain as such, but these are not my favourite from your stable. This sierra hardware is not one that followed the original design brief in that the curvature finishes before the wood starts. I would normally cheer from the rafters that there was a slight belly, not an enormous one (in the wood), but just a gentle curve that continues the curve on the nib assembly. Unfortunately the curve on the nib assembly is flat at the point where the wood takes over and on this occasion I think that the wood ought to be straight, otherwise it just looks odd. Dont know if it is a trick of the camera but is the wood proud of the centreband?