If the Front standard is not square to the bed and body then moving the bed out of square will not fix the problem. Moving the bed out of square will induce rise or fall and the front standard error angle may come back into play as the lens focus is changed from the point it was when the bed was repositioned.

Bed Check

45PSS wrote:

If the Front standard is not square to the bed and body then moving the bed out of square will not fix the problem.

To be clear here, the front standard is square to the bed.

But the bed is NOT square to the body.

I loosened off the plate bed braces and managed to get the bed sitting a little closer to square but it's still not spot on.

I've dissassembled the bed assembly and am now reasonably sure that the bed second is bent at the forward edge of the right hand side bed brace.

Will gently persuade it back into true with some wood blocks and a mallet later.

I managed to fix the rangefinder alignment...

I focussed the lens at infinity using the ground glass, then removed the top RF housing, loosened the grub screw on the armature connecting to the rangefinder moving mirror, rotated the mirror until the images aligned, then tightened the grub screw.

All appears to be well, probably not the ideal method but better than trying to cut a master cam.