Pretty much exactly my plan... Except I was just going to write down measurements from a micrometer. :)
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Here some history about your frameback "Au Diamant".
According to the Cutlery trademark registration office in France, the trademark "Au Diamant", was registered in 1889, by Vital Hygonnet from Thiers France.
Attachment 113320
Mr Hygonnet was allready a reputable cutler before the time of his "Au Diamant" registration.
Attachment 113321
As you can see on this receipt from 1890.
In 1896 the firm change name to Vital Hygonnet, Pere, Fils et Gendre, (father, sons, and son in law)
Attachment 113322
In 1900 a silver medal at the exposition.
Attachment 113330
Attachment 113331
(1893-1902) A short lived family business!
Wow, that's a really lovely trademark registration form!
(one of those things I never expected to type...)
If memory serves, the German Salamander Works was nearly as brief. I am especially fond of these kinds of ephemeral companies.
All right, since you asked. You can see a couple pics here. But I'm warning you, it's not nearly as pretty as Zak's.