Some very good ideas here, but for the love of easy, shim the durn base! Easy.
Guys used to do this for long range shooting ALL the time before 20 and 30 MOA scope bases were available. You might need longer screws, or you might not. This is not just a good solution, it's a great solution. Don't honk the scope rings down super tight yet (which in theory might mark the scope tube, shim the base until you're somewhere in the middle of the scopes adjustment range, then, if you want to be anal, lap the rings (with the scope bases at their new height).
I have done this many times, used beer cans, Devcon, beer cans plus devcon, etc
