Were you there when Johnson got his dies, maybe they came from Heiser

Were you there when the sheaths were sewn to tell the stitch differences?

My point is, provenance is a link between then and now. Your link is only your opinion, and you are hoping that "years of experience handling them" will convince others.

That would be fine if you considered the manufacturing clues that are obvious, that tell us, without a doubt, who made what.

You see Joe, I manufacture flutes, by hand, one by one.
I know how to distinguish one flute maker from another. I look at his technique, not the type wood.

Manufacturing clues Joe.