I made a hatch in the rear of the fuselage too. I am using a 4 cell 4.8v 1000 mah batt. pack. It was still a tad nose heavy and I added a few ounces to the tail group, just in front of the v-stab, under the tail fairing. Now it balances right at the recommended 4 inches from the leading edge. I also made the mount for the batt. so that I can shift the batt. a little fore or aft to change the CG as needed.

I mounted the rx in the area intended for the throttle servo. Since I mounted the throttle servo up front near the firewall, the stock throttle mount was the perfect area to mount the rx.

All I have to do now is get an rx switch and mount it and she will be 100% flight ready.