A few years back I posted a cabinet drawing for a simple model 19 clone. The hosting service sucked and my HD crashed so I don’t have it anymore. If someone has a copy it might work for you. Leave out the slot and tune with standard ports. It will also take a set of M19 foams which are a good idea to use. For the 416-8A the Onken cab is nice but those are huge and heavy. On the plus side since you top mount horns with this box you can swap them out pretty easily and certainly won’t need a sub for music.