I have posted some of the following info. on a different thread and hadn't checked this one for awhile. I had to add 15 oz. to the tail to balance out the G-38 up front. That put the ready to fly (less fuel) weight at 17 lbs.
I now have 4 flights on this airplane and here are the results. After a somewhat scary first flight, I adjusted the ailerons for more throw than recommended. I am used to flying aerobatic airplanes and this Cub is not one of those. It doesn't have a lot of aileron authority and when it does finally start to roll, it is SLOW. The rest of the flight control set-ups worked well as recommended except for the flap / elevator mixing. The nose pitched down slightly with the recommended mix so I took out a little elevator to end up with about 1/4" down elevator with flaps down. I also set up a high rate elevator with a lot of throw just to help keep the tail down while taxiing. I switch to low rates just prior to the take-off roll and leave it in low rates for the duration of the flight.
Regarding the weight installation, I cut a hole in the bottom of the fuse, epoxied and screwed the weight onto a hatch cover, and then slid the weights into the hole, and then epoxied and screwed the hatch cover to the fuse.
I intended to put the kill switch right in front of the servo tray with a push / pull rod coming through the fuse. I must admit that instead, I set my tx up so that the idle trim will kill the engine.