[Lugerdoc]

Andrew, The fancy Franktur "S" inside your left grip does indicate inspection at Mauser, probably around 1934 and the asterix mark indicate it was made as a replacement spare. The E/6 inside your right grip, is that of an inspector at Simson during the Weimar period. It's hard to see all of the serials in your photo, but a #99 safety bar isn't correct in a frame serial ending in 77. If your frame, receiver, barrel & toggle assy match, I may be of assistance helping match the small parts.