1917 ERFURT P08 Luger

[lugersrkewl]

Hi , the mark on the barrel is an erfurt proof mark typical. The yellow on your letters is just oxidized or the like. You can buy a new stick of machine marker and reapply if yant to.
You have a hold open on your gun it may not be bent at the proper angle you will have to pull it out careful of springs or parts flying out and gently manipulate the bend and reassemble repeat until action stays open. It might be that your magazine spring is worn and the follower doesnt have enough power to apply sufficient pressure to the hold open. A new repro or other mag or replacement spring may be required but try cleaning and tweaking the holdopen first. heres a pic of the holdopen. looking closer it might even be broken. should be a solid piece. woudnt hurt to clean with hoppes and q tips then a good coat of oil in there either.