Identification of hallmark on French silver

The box also has the “Minerve 1” but this appears right next to the unknown mark (see image below). There is also a diamond lozenge Maker’s punch mark elsewhere on the box which under magnification reads (I think ?) “Ste” an “P” with what appears to be an image of an arrow or a dagger in between the lettering “Ste” amd “P”. Any help would be greatly appreciated. Thank you.