Re: How much deck over the cabin do I remove?
Umm, ouch. That looks bad, really bad. The rot at the keel/hull joint may be terminal if the rot at the deck/cabin trunk line isn't. I've cleaned up really really dirty smelly boats before, but I did so knowing that they were sound hulls. I don't think I'd spend 10 minutes on this one. I'd salvage the rig, motor, and whatever I can unbolt from the hull and get rid of the rest. Sorry to be so blunt, but if you want to go sailing, there are much better ways.