BVM Super (Balsa) Bandit
The upper hatch retention is done by having two spring-loaded hatch latches at the front end, and 4 slide-in retainers at the rear.
The rear is done first, starting with two 1/16" wires and then adding two canopy hooks.
Note that in general when dealing with fibreglass / composite structures you should ideally keep the hatch, canopy etc taped to the fuselage during the initial wing construction etc., otherwise the parts fit may deteriorate slightly over time.
Take a moment or two to check that the parts fit is still okay, and see whether you need to e.g. apply a little inward pressure on the fuselage sides to get perfect alignment of the edges. You need to do this before drilling the holes for the pins, as the correct fit will be helped by the proper placement of the pins.
For instance, in my case I had left the hatch off for a while, and the fuselage to hatch fit was now 1/32" off, width-wise. Slight pressure on the fuselage sides made the fit correct, so I simply ensured that I applied this pressure when marking the holes for the pins. That way, once the hatch is slid into place, the pins hold the structure correctly aligned.
After the pins, you add the rear canopy hooks. I found the method of gluing the hooks in and then marking the slots slightly awkward, and did this instead: With the upper hatch in place, I reached inside the fusleage from below (through the belly hatch) and transferred the slot position from the rear of the hatch to the fuselage flange. Then, after cutting the slots, I again positioned the upper hatch and reached through the belly hatch to glue the hooks in place as shown.