I've wanted to do this for some time, and finally got everything together to do so. I used solid ash with book matched top and bottom panels and finger joints for the carcase corners. I used a water based grain filler on the outside of the box, then finished with 7 coats of clear lacquer. I wish I'd have thought to fill the grain on the underside of the lid prior to assembly. Oh, well.
The biggest pain in the kiester was getting the felt/foam insert done. It isn't perfect, but good enough. I tried several different methods, including a liquid foam but didn't get the results I was looking for. I settled on using 3 layers of 3/8" EVA foam with the gun cut out through two layers, the magazine cutout through 1 layer. The felt on the bottom of the cutouts was cut oversize and glued between layers. The sides of the cutouts was glued, then the covering was glued over and cutout once in place.