Nice, the same one I had and easy to use. Why they ever got beyond 3000 yds for the GP 75mm is a riddle. The gunner had to adjust his sight on the reticle depending on the ammo....For HE or WP, had to aim a couple mils higher as the sight picure was based on AP ammo. Same technique for the 90mm on the Pershing ,M-36 & M-46. The side dashes were lead lines for tracking a moving target but rarely did the gunner go beyond the first as the speed of most targets was slow. Took a bit of training to be an accurate gunner and since the scope moved with the gun cradle, the gunner had to really cramp down when the gun was elevated. It was not articulated like the tiger. . Nice find and thanks for posting. Brings back memories.