NEED HELP - proof marks on a French 16x16 Cape Gun

Hello All,

I watched this one advertised for nearly 2 years. I finally decided to bring it to Wisconsin.

This is the fifth Cape Gun in my collection.

This one looks to be very high quality. The unique sling feature is cool.
A spring wind-up stores it in the stock.

I have no clue what all the marks mean, but I'm sure there is a lot of information there.
I have shown all the markings on the gun. I could find no others.

Can anyone help with the interpretation please?

And, your comments are always welcome.
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HERE IS THE ORIGINAL ADVERTISEMENT

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