The maker is Ewald Lüneschloss, Militäreffekten-Fabrik of Solingen. The trademark is a Neo-Runic interpretation of three upper case L letters, each constructed as two sides of a triangle. The symbol is sometimes referred to as a "hakenstern" which the firm additionally used as a trademark name. They also produced bayonet belt frogs (S. 84/98) during the year 1934. Attached is a period advertisement for the firm from my files. Hope this helps ......
Turning your picture over sure appears to show a 1934 date. Nice sling!
Nice info Slash. I had not seen that one before. Did they continue after 1934 or start making other leather goods?