BUIS at 45 degrees, not quite

I've installed a couple of 45 deg. adapters, attached to the top rail, to put the Magpul BUIS on the right. The first adapters (Burress) didn't move the angled rail section far enough over to clear the rear of the Leupold scope. Next I got a second NCStar adapter (I know, but it's not optics, it's just a 45 degree adapter...) and now the sights clear the scope, but I can't get the sights on target. The rear is over all the way to the right, and it's the hits are still an inch and a half too far left. So, I'm thinking (again, I know, but I can't help myself) that some stainless shim stock, bent in a V, and installed on the right side of the rear rail, to move that sight to the right.

Does this sound about right? If I could only find that shim stock I've had for the last 35 years, and moved oh, so many times.