The short description: I removed the extrusion that the bed rides on and stuck about 3/4" into a vise. I used a large pipe wrench to twist the extrusion, attempting to go just beyond the modulus of elasticity so that there was a small change in the twist. I was quite lucky in that I hit it fairly closely, I probably couldn't do it a second time if I tried.
This is the result of the modification, the bubble level shows that the bed is staying fairly consistent in the X Axis as it moves along the full length of the Y Axis.
There are 2 bumps in the extrusion as the bed approaches the 2 limits of travel and there is a small shift in the X axis when the bed crosses over these point. About 1 inch at the front and back extremes of the bed are out of calibration and can't be reliable used for printing, other than that, it is working fairly well.