Marriette Early Percussion Revolver

[RobertGuy]

Up for consideration here is an early revolver type pistol.

Catalogue description:
Scarce French Mariette Percussion Revolver by “Devisme”. Five 41/4 inch, 80 bore screw off barrels. Breech with straight nipples Rounded steel body with scroll foliage engraving. The top with gilt filled maker’s name “Devisme A Paris”Steel grip frame stamped “Mariette Brevette”. Steel ring trigger. Polished bag shaped grips. Action AF.

My stats:
Weight: 1lb 8oz (0.68Kg)
Bore: .38 inch (9.6mm), 80 bore?
Length overall: 9 inch (22.5cm)
Barrels : 4 1/4 inch (11cm)

Foliage engraving on body and backstrap. Numbered barrels and corresponding mounts. Two proof maks on rotating portion of the action. Gilt makers name on top of Body, “Devisme A Paris”. Underside of grip frame stamped “Mariette Brevette”.

The pistol is just about in working condition. The action is worn and unreliable but there is nothing actually broken or missing. The barrels unscrew and are numbered to match up with numbers on the mounting.
Can anybody give an accurate date for this and any info on the maker and proof marks? I believe that Mariette is the patent holder for this particular type of revolver