Allow me to retract at least most of my last entry and apologize to our Asian friends. Oh...and admit to being a dope that goes off half-cocked...

I was looking at the edge along the base near the mounting surface - which is not really a reference surface, I don't believe. In checking the side of the rail where the balls ride, I get less than a thou over any 6-8 inches. At this point, I am just going to start on the gantry mounting and check it at different points as I go.

Regards,
Wallace