I've got a new gun case but don't like the foam inside. The foam was like pre-cut to fit a rifle and it doesn't work for my rifles. It has a place where one rifle fits in the bottom of the case, and one in the cover, and I don't like it. I want to get some closed cell foam and make my own. The dimensions are 15 X 50 X about 3 inches thick. I found some closed cell foam on Amazon, but it looks like upholstery? Could use some help/advice with this one.