Hi Fernando,
This is getting away from the original thread which discusses the beautiful pistol you have. I agree with the comments that proof was not made mandatory until 1810, but the first proof mark (the Perron) was introduced in Belgium in 1672 for inspection/proof of breeching systems. It was not used on revolvers. France had proof marks from 1782, so they are not new!
The problem remains as to origin of your pistol. Have you removed any of the screws to see if they are hand cut or machine cut. This might narrow down the age somewhat. I think we agree that flint ignition was superceded around 1830 so they would be earlier than that. The other comment I would make is that although they are marked LONDON, I don't think that they are of English manufacture for 2 reasons. One is lack of proof marks but they other is that they don't appear to have an inset escutcheon, on which the owner would normally have his name/initials engraved.
THE PLOT THICKENS!
