Thanks for the info.
I can't detect a wobble unless I simulate an end cut on a 3" wide board. When I move it through this slight dip, I can feel it drop in ever so slightly. Hardly detectable. However, by the time it's at the router bit's position in the table, it's on the flat again.
The cast aluminum top is anodized and has a dark gray surface. I really don't want to ruin the coating by sanding it. It is 30 years old and has survived so well, I just don't want to invite new problems like bare alumininum "marking" the wood.
My first router table project will, in fact, be stiles and rails. That's why I'm concerned about the accuracy.
Thanks again. Joel