I need a big wedge or something to raise one end of a shelf unit up about 1/2 to 3/4 of an inch. The unit is 30" wide and 15" deep and about 50" high, no doors, so not too heavy. It's part of a wall of RTA wardrobe and shelf units. I probably will attach it to the wardrobe, which will be attached to the wall.

Problem is, along the adjacent wall in that corner the floor butts up against another slab and is buckled. It messes up the level for more than a foot, so I can't just move the unit over a little. Anybody got a suggestion for a somewhat permanent fix? Thank you.