John Walter's Rifles of the World mentions (briefly) F.W. Kessler & Co. of Suhl as making "an unusually narrow action set in a one piece stock."
However he reproduces a drawing of one from a 1911 A.l. Frank catalogue, and not only is it a target-style rifle - half stock, aperture rearsight, set trigger and elaborately spurred trigger guard/lever - but the distinctive curved top of a recognisably Martini breech is visible protruding above the stock, which that example doesn't seem to have.
Iain