Blitz,
The snap closure were an interesting affair to say the least. I wanted to make to upper hull easily removable, yet secure enough not to create problems on the battlefield. Now I'm no engineer so I just started brainstorming and thought I would experiment. What I ended up with are a couple of different closures that work pretty well, it's easy to open, the hull stays together pretty well, but it is a pain in the rear to line up and securely snap down. So now I'm thinking about adding some strong magnets to help align and secure the two pieces more quickly. So I'll break this down into sections.

Front edge of the upper and lower hull.
I epoxied short pieces of aluminum tubing in the lower WSN hull that line up with the stock mounting posts of the upper Trumpeter hull. You simply slide the plastic mounting posts into the aluminum tubing and they hold quite nicely.

Rear deck of the upper to lower hull.
In the inside edge of the upper hull I used styrene to make an "L" shaped catch bracket, which lines up with a corresponding styrene ledge in the lower hull. For assembly you line up the post and aluminum pins at the front, and pivot the back section of the hull to capture the L bracket under the ledge or lip.

More to come on the side catches