Dwight
Its a fairly common marking. Here are a couple of Lugers marked as you described:
*1911 DWM, s/n 1166e : B.1.T.S.3.171. - (Bayerisches, 1 Train-Bataillon, Sanitäts-Kompagnie 3, Waffe Nr. 171)
*1911 DWM, s/n 1046e : B.1.T.S.3.68. - (Bayerisches, 1 Train-Bataillon, Sanitäts-Kompagnie 3, Waffe Nr. 68)
Jan
Its a fairly common marking. Here are a couple of Lugers marked as you described:
*1911 DWM, s/n 1166e : B.1.T.S.3.171. - (Bayerisches, 1 Train-Bataillon, Sanitäts-Kompagnie 3, Waffe Nr. 171)
*1911 DWM, s/n 1046e : B.1.T.S.3.68. - (Bayerisches, 1 Train-Bataillon, Sanitäts-Kompagnie 3, Waffe Nr. 68)
Jan