Owosso, http://www.ganoksin.com/gnkurl/ep80h9 is the place used for
my engravings. In my early career as a photographer/photogengraver for
a newspaper, my job was making zinc engravings. I sure don’t miss
working with nitric acid.
You might also want to consider investment casting photopolymer. One
of my YouTube videos shows the process used for some of my castings,
both for making a vulcanized mold for wax injection or investing
Hope this helps