Hello Fireman,
Everybody is going to call me crazy, but this actually worked. I put a C-clamp in the middle of the base and tightened it down a little at a time until I could get the screws out. I put a small steel plate and a piece of plywood between the bottom of the monoblock and the clamp, and some plywood and padding between the clamp and the top of the base. I guess it relieved the pressure enough to true up the scope mount. Hope this is of some help.
Best,
PDK