I used the same rectangual design that I used on the Old City Hall SG panel, but decided to try chamfer the inside of the front, so it tapers in to the SG panel.
OOOPS...........I put in a red chamfer bit with a roller bearing guide on the router table, and tried the first piece of the front frame. DARN......when you start the cut and end the cut, you get a divot on each end because there is nothing for the roller bearing to guide on, since it is a 45 degree angle on the end of the boards.
I salvaged the pieces by sawing a 30 degree chamfer on the table saw. If I try this again, I should chamfer the 4 pieces before I cut the 45 degree joint angles on the ends with the miter saw !!