Originally Posted by philipat

The biggest piece (folded into multiple angles) screws into the center post on the front of the upper hull. It slips under the bracket on the front of the lower hull. The other two assemblies screw onto the rear posts that you circled. Two bent pieces come together to form a bracket. The flat piece with flanges slides between them. The flat piece has a flange (hook-shaped) that goes at the back or towards the centerline of the tank and pointing down (when the upper hull is right-side-up). The spring hooks to that flange. One of the bent brackets has a similar flange and goes towards the centerline of the upper hull. That's for the other end of the spring.

I have this hull on PzIII. It's a good latching system in that it is secure. But, I find it rather inconvenient when I have to open it to change the batteries. I'm going to replace the latches with magnets glued into the corners similar to what I did on my PzIV.