Thanks, David. But, the computer does all of the work.

Ok, status update: I've reduced the height of the "legs" or "walls" on the plate from 3/8" to 1/4" as Ron requested. And, I've emailed him the STL files that, supposedly, will let him have Shapeways make the two parts.

And, for closure, here's a view of the plate with the shorter legs:




Whew!