Hi Guys, I finished the re-build on my Seagull Zero. SUCCESS !!! By knocking out the former inside the engine mount box, I was able to put the battery in below the thrust line. (In the bottom of the box) I made two bracket arms out of 1/2 X 1/8 X 6" aluminum and mounted each to the lowermost sides of the box. I added some wood to the inside of the box to have a more solid mount. I cut three Prather stick on weights in half and removed the double sided tape. I drilled and screwed three half-sections (each 3" long) to each bracket arm and mounted them so that they came flush to the end. I left room to mount a fourth piece if needed. With 9 ounces of lead as far forward as I could get it, parallel to the leading edge of the wing, a K&B .40 with an 11X5 prop pulls it around surprisingly well! The complete fuselage with radio, cowl, and engine w/ muffler, without the wing attached, balanced like a football! Attach the wing, and the lateral balance comes right to upright dead center from any angle. This arrangement allows for good CG balance as well. It is much more stable, and I'm not afraid of it anymore. It's fun to fly!! Make sure you mount the weighted bracket arms with the engine and muffler attached so they don't touch any part of the engine, muffler or cowl. Bend to adjust if needed.