Found this much out, the one eagle to the right is "Luftwaffe" acceptance mark. the biger version is on the actual gun.
Someone also told me that it is not sure that there will be any "nazi" markings as the 151 was being manufactured already before the war and that luftwaffe and heer had total diffrent ways of marking items, they where not even allowed to buy from the same factorys.
Thanks a lot, after a couple of 100 hours on google, I already know what kinda jungle there is with markings. Was just taking a longshot that some of the "waffle" guys would have a hint.