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That one don't have flotation, you have a lot of possibilities there of how to work on the transom and stringers. I'd suggest putting inspection hatches in the floor to work from in conjunction with redoing the transom and foam the bottom when done.
Aw heck, just look at some of these and start asking questions.
And I'm nowhere near complete fixing and upgrading mine.
http://www.wellcraftv20.com/communit...ead.php?t=2808
http://www.wellcraftv20.com/communit...ead.php?t=4901
http://www.wellcraftv20.com/communit...ad.php?t=10134
http://www.wellcraftv20.com/communit...ead.php?t=9309
http://www.wellcraftv20.com/communit...ead.php?t=7586