The drawing you received has been made by the end-customer. The end-customer is currently producing these parts by welding stainless profiles together: that’s why you can see on the drawing “welding lines to be invisible antique outlook”.
It doesn’t have anything to do with your technology since you are using Stainless wax die-cast à there won’t be welding lines with a die-cast.
As for the material, I have already replied to you: you can use the same material as the “pattes a glace” project that you are currently producing for us.
Awaiting your price quotation