Hard to imagine why Bannerman would convert M 1874/M80 to M14 8mm Lebel for a North American market. One would think 30'06 would be a more profitable choice for the company.
GRAS série X
Les armes de théorie série X, faites avec des pièces rebutées ne portent pas l'estampille de la Manufacture ni les poinçons du Directeur et du Contrôleur Principal. Elles sont destinées à l'instruction de base des troupes. En principe, on ne tire pas avec ces armes.
Les Gras scolaires des série U, V et X étaient fabriqués sur une base Chassepots transformés.
Leur poids était diminué en réduisant les dimensions du fusil et celles des garnitures. Pas de tenon de baïonnette. Hausse modèle 1866 réduite et graduée de 10 à 40 mètres. Chambre courte ne pouvant recevoir que des étuis raccourcis de 10 mm chargés comme les cartouches de tir réduit.
Source : LES ARMES À FEU DE L'ARMÉE FRANÇAISE 1860 À 1940 par le Colonel Jean Martin, Crepin-Leblond éditeur."
The above French text describes the x numbered series rifles has training rifles made up of inferior or rejected parts and are not meant to be fired. Explains the condition and the lack of arsenal markings on the receiver. Of no interest for Shooters, but still a good piece for advanced French Arms collectors.
Your translation is incomplete, two different guns.
- The Fusil X series Gras de Théorie are a complete rifle made from reject Gras parts to replicate functional rifles. The rifles were used by the French Military as training aides.
- Gras scolaire (School Gras Series U , V and X were made on a converted chassepots frame.)
are made from Converted Chassepots are another type of rifle made for use by School Cadet Corps and not the French Military.
If you absolutely have to fire it, have the barrel, bolt and receiver magnufluxed to check for possible metal defects. I suggest you sell it to an advanced French Arms collector who will know what he is dealing with and preserve it for future collectors.
No point in arguing about this, but in final analysis official French military records do not lie. You have X serial numbered rifle, with no Arsenal markings and no proof marks, so its an official Fusil de Théorie. Since its an Arsenal produced training aid it is normal to have matching serial numbers. Even today France has strict Proofing Laws and any commercial or military rifle meant to be fired will be proved at the Arsenal or the Banc d'épreuve de St-Etienne. Fusil de Théorie are not common and you have a superb specimen so you will still get a good price fot it.