A 12lber cast at Valence (Drome) on 11 Germinal An 2, as No. 19. It is marked as weighing
“P.1871D.” It is number 156 on page 53 of the 1911 Petrov catalog.
The most interesting part, in my view, is the remains of the ‘hausse’. Clearly NOT one of the several Gribeauval designs. The scale is engraved on the left side of the mortise. There is only one screw hole (the Gribeauval had four or five screw holes), I assume it was for the wing nut that held the sliding part once the elevation had been determined. There must have been a point at the bottom of the slider that aligned with the engraved markings. Interesting!
We also have illustrations of some of the other markings on this same piece: