STOGOS = Stotz & Goessel, Suhl, was founded by Johann Stotz and Leopold Goessel in 1923. Business: Gunmaking, import (fom Belgium), export, wholesale of hunting-, target arms, pistols, revolvers, ammunition, hunting equipment, handloading stuff, edged weapons and so on. 1927 Goessel left the partnership. Shop only sold to a Wilhelm Knopf in 1930, end of Stogos. The rifle was most likely made by Schüler for Stogos. Take the rifle apart and watch for the proof- and other marks under the barrel. Richard Schüler, who ran the A. Schüler OHG company then, made many bolt action rifles for others. Some time ago I saw a .404 rifle, marked on the barrel by Jeffery and with London proofmarks, underside of barrel marked "A. Schüler" and Suhl proofmarks.
BTW, if the original bolt can not be found, any 98 standard length bolt with the 8x57/.30-06 12 mm bolt face recess will do.