"Sneak" Luger

[tx_oil]

Ok...I took possession of this Luger today, after a close inspection, and I'm pleased to announce that is is a numbers matching piece. It has the mauser hump, has had a mag safety installed and grip notched, and safety was removed at some pooint later. I will take some good clear close up photos and post for the edification of the knowledgable folks. It has no markings on the toggle, no chamber date, but a serial number under the barrel, and the number has a "u" suffix The grips are wood but so dark they are almost black, no numbers or stamps on the grips at all. I shot it today, and it functioned flawlessly on 115 grain ball ammo.
However, the bullet point of impact is considerably higher than point of aim...about a foot higher at 4 yards, and 2+ feet high at 25 yards. Is there anything I can do to adjust the point of impact with the sights??