Final details on the flag box include fitting the back frame to hold everything in place and making the French cleat for hanging. I probably don’t need a French cleat, but using it will help prevent the box getting unintentionally knocked off the wall.
When shooting mitres, I use two different mitre shooting boards and I haven’t talked about the Evenfall picture shooting board that I use and comes in particularly handy when I need angles that are different from 45. Silly me build my flag box not at a perfect 45 degree angle. But have no fear, the Evenfall picture shooting board is adjustable.