I picked up my Dust Deputy from Ace today, got it home and found a bucket to use, and measured up the hole patterns.
I went with a center 3 1/6" hole for the center, and six 5/16" holes centered on a 4 5/16" pattern. Did a quick drawing in vcarve, screwed the lid down in the center and zeroed out on top of the screw head (not really, just really close to it).
Still need to decide how I want to make it mobile, either on a cart for both it and the shop vac or by itself.
Attached are the vcarve and gcode files. I used a center datum (starting point), with a 1/4" depth of cut in two passes with an 1/8" two flute end mill.