Hi everyone,
I have finally managed to obtain images that confirm the chronological section of the box's elaboration
1.- Charge mark: Jean Baptiste Fouache 1775-1781
2.- Release mark: Monkey head (tête de singe), 1775-1781 (Jean Baptiste Fouache office)
The following images are the ones that offer more doubts.
3.- Master goldsmith mark:
A capital A is seen. About her a point.
The most frequent name of French goldsmiths is Antoine. I have located the marks of three goldsmiths of the time whose first name begins with A
The fisrt one belongs to Antonine Boullier

The second one to Antonie Gaspard Loret
upload photo
The Third to Antoine Dutry

Neither candidate convinces me. Maybe some of you can help me
4.- Guarantee mark (Paris): crowned letter
I'm not sure but the best image I have been able to get with contrast is the one I show you, I seem to guess an N (Paris, 1776-1777)
The last image corresponds to the N of another gold snuff box so that you can compare.
Thanks for your patience
Regards
Jaume