There were a number of makers of the M1 Carbine during WW2, incl Underwood and Inland which produced the largest numbers of them. All US military Carbine parts are interchangeable regardless of maker. Any make of military bolt and any style , scalloped top or full round body, will fit any military carbine. The key thing when fitting a bolt is to make sure that the headspace is correct with a particular bolt in a particular receiver. Both "go" and "field" dimension headspace gauges are required for this.
From your description it sounds like you may have one of the Bavarian Police model Carbines which were used by the German police after WW2. One key identifier of these Carbines is the installation of a vee type open sight in front of the receiver, rather than the standard aperture sight on the rear of the receiver. Contact `gunsdora`who normally has a pretty good supply of carbine parts on hand.




























