RE: Seagull Zero
[link]http://www.rcuniverse.com/forum/m_1366941/anchors_1366941/mpage_1/key_Seagull%252CZero/anchor/tm.htm[/link]
Try this thread. There is extensive discussion about the CG.
Mine flew fine with the CG 1" behind the main spar at the fuselage.
Good luck