I’ve enjoyed several of your books.
I wish I could give you something definitive, but now that I dig
through my references, I can’t find anything solid (in print)
earlier than you’ve already found.
My one suggestion is to try the city museum in Basel. I was there
about 20 years ago, and they had what I (dimly) recall was tagged as
a 16-17th century jeweler’s workshop put back together as a display,
and it had the typical four place workbench with the crescent
cutouts. It was down in the basement, but that’s as much of a lead
as I can give you.
Hope that’s of some use.