Many thanx ! S for SEPTEMBRE !
Cannot be MARS becauseas KELT said "it was made at MAS (Saint Etienne arsenal) in 1891 most likely in the 3rd quarter"
Before your carbine we had already my carbine S/N F562XX which was finished in august 1891 and after, we knew already 1886lebel's carbine S/N F841XX which was finished in November 1891 and VIVELACOLO's carbine S/N F9336X which was finished in January 1892.
All that is missing is the steel supplier, the MAS director and the main controller (punches just above the serial number on the barrel), and your weapon will be perfectly identified!
Just right above the letter prefix and the serial number in large block letters is either a one or two letter code for who provided the steel for the barrel called as the pourvoyeur de acier as steel was provided by various private manufacturing steel milling / forging firms … JH is for Jacob Holtzer et Compagnie à Unieux
To the right of the steel suppliers code are two circled block letters that show who the contollers were at the time of the manufacture of the firearm, these were called Controller Stamps called as Contrôleur Poinçons.
The first circled letter is the first letter of the last name of the Overall Supervising Officer of the Manufactory commonly called as the Director of Manufactory (Directeur de Manufacture) when the barrel was made for the firearm. P is for Colonel Percin
The second circled letter is the first letter of the last name of the Final Arms Inspector or also called as a Principle General Controller (Contrôleur Général Principal) when the barrel was made for the firearm. We do not know the vast majority of the people who held this position at the national manufactories as records are lost, missing or destroyed.