You stated you had loosened all of the nuts and screws so this probably wont help but did you loosen the screws that hold the front "bullet" pin in place, there is some adjustment side to side in that mechanism. If nothing else fails, Id try completely removing the ramped irons that engage the "T" bar and see if it fits any better. That will at least give you an idea of where the problem may be. If these are modern reproduction glass tops, they should certainly fit without the effort you are describing but they WILL NOT fit as well as the originals and are designed to sit up about 1/4 inch on the back side where the tops meet the halo frame at the back window.