It sounds like at some time the turret has been crashed. It sits on a wedge and if hit hard enough will move up on that wedge not allowing you to get live tooling on center. You'll have to take all the sheet metal off from around the turret. Put a gage pin in an axial tool holder making sure that the pin runs true. Have an indicator in the spindle to indicate the pin while you move the turret (don't use a mag base). You'll want 2 tenth indicators down low on the turret casting to make sure your moving both sides equally. Loosen up the wedge and hit it back with something heavy. Using the hand wheel to keep the pin on center until it indicates true. Snug the bolts down, check for square, tighten everything down, put your sheet metal back together and start making parts. It will probably take a day to day and a half to get it right.
Good luck, Dennis