My first thought was John Derr, Angstadt, or someone associated in that area, only a hunch based on the patchbox finial, which looks like an exaggerated/devolved version of those used in Berks co (and northwards?) in the 1820s. I was trying to find photos on my computer of a Derr that had an Angstadt-looking patchbox, but it's not where I thought I saved it. What's the sideplate look like? Any incised work on the cheek?
-Eric
