Clear mastic couple tubes and mastic gun apply inside along the edges but you should remember
(a) some of the sheets may have slightly slipped.
(b) rubber sealing strips on the outside my be rotten and need replacing.
(c) sealing the inside rain will stilll seep through the old outside seals and eventually rot the wood frame if not rotten already so best get someone out to give it a check out. And in my opinion you don't need to replace the polycarbonate just the rubber seals and maybe underside spacer strips if any.
B
November 2010