Hi Gunter,

I don't think I can offer an explanation, but I wonder if you're not pretty close to a usable pattern with what you've done with Brian's help?

I don't know how precise your model and pattern need to be, but first I note that your model is made of sheet a bit thinner than 1mm. The edge thickness is 1mm, but since the edge is not perpendicular to the surface, the sheet is thinner, ~0.84mm

Will you form it over a cone mandrel of the same angle as your model? If so, wouldn't it just be a matter of unwrapping the inner surface and ignoring the outer surface? Use the resulting pattern to cut the silver and then form it over the mandrel?

--Larry