I have built 2 Dazzler kits and I installed a screw attached hatch at top for access to tank. I used hard balsa stringers for turtleback, and rudder. What I didn't do but heard from some on RCU was to: install engine far back in engine mount since aircraft tends to be nose heavy (good idea) and use a built up landing gear to replace the wire type landing gear. The wire landing gear spreads easily but I only need to adjust once or twice a year. I also heard someone on RCU say to extend the balsa planking on the wing out to the next rib to reduce the the mid resonance sound. I didn't do that either. Some install larger rudders, I didn't.