I would say that the engraver was Z-M mechanic Gustav Ernst, but he passed in 1899 so for sure it was one of his students as he was the Master in the Z-M area. Now have I seen an Oerhring mentioned and possibly with a family relationship it could have been him. On the floorplate / bottom side of the action the engraving is very similar to that of „Raschsche Karreegravierung“, or Rasch's Square Engraving.

Cheers,

Raimey
rse