I posted this question about 18 months ago with no real results so I thought I'd ask again in case there are new members that may have the answer. My 1917 is a .380, no lanyard ring, brown plastic grips with the Indian Head/Raised Rifle logo. Legend is correct for the time period - mfg about 1928 (sn: 29168B). The are 2 marks that I can not find info on. Both are shallow and larger than the factory markings. On the left side of the frame is PQ. L-511 and on the backstrap this is R99. Any help with the markings would be greatly appreciated.