Hi Gunter,

I think I'd fix the model first, making sure that it is using a 1mm thick sheet.

If you're concerned about the size, maybe it would make most sense to make a cone through the mid-thickness of the model's sheet and then unwrap that? Similar to how you'd plan bends in other stock, use the middle line allowing for compression and shrinking of the inner and outer surfaces. Trial run in brass certainly makes sense to verify result before working with the silver! What is it that you're making?

_ConeUnwrap is a neat script Brian!!

--Larry