A router with the correct bit to follow the circle of the woofer cutout made cutting the QSC waveguide easy. A bit of sandpaper on a old port tube finished the rough router cut.
The baffle was spaced to come out exactly even with the front edges of the cabinet sides. The edges of the sides still are angled back at about 15 degrees, but are only 3/4 inches wide, so are difficult to see. The spaces between the baffle and cabinet edges were filled with ZAR wood filler, sanded and then the entire front was veneered.
There are also magnets epoxied into each corner of the baffle for holding a grille, should I decide it needs them.