thank you so much Rainbow1969 for a gr8 response – lots of good info there. i had observed that the rod-tops @ keelson lookd normal, excellent suggestion about giving them a turn or so 
i actually got in there today and started removing bungs and screws, (from bottom boards) and as soon as i got to the keel area, sure enough, the screws were severely keyholed and just barely holding -some had held fast to the keelson, and pulled through the boards, but most had stripped out of the big beam. reckon some bigger screws (about 500 of them) and a few new boards and we’ll be good