Boat hull ribs how to repair?

I have started to look after my grandads boat (motor sailer 24 footer) since he is living about 300 miles away and we recently had a miss hap, the board we have as a rubbing streak got caught in the staging and held the boat at a angle in the spring tides and water got on board to approx 1 foot above the galley floor when I pumped it out and opened the inspection hatches that was cut into the floor I found that the GRP ribs that stiffen the hull had been cut to allow the floor to be placed in and not recovered with grp as a result the wood has started to rot since they have been left open for such a long time and not sealed back in.

I know I would have to strip the galley and bed/seating area out and replace these or would I place sister ribs in maybe oak?? (dont know what wood is best) bolt them to the existing ribs and grp them in or is there another method of repairing these?

Along with this I have noticed inside the fore cabin there are patches in the grp where it seems thinner then the rest does this need looking at? or is it a manufacturing thing here they can not make the same thickness all over the hull? maybe a grp filler to make it thicker in these patches?

I am also reinstalling all the electrics as he is old school and made a electrical panel himself (about 25 years ago) for the 12v electrics but I prefer a more modern one..


more photos:
http://dl.dropbox.com/u/96342635/IMAG0376.jpg
http://dl.dropbox.com/u/96342635/IMAG0377.jpg
http://dl.dropbox.com/u/96342635/IMAG0373.jpg

Ayuh,.... You could fab up new bulkheads, 'n stringers outa plywood, 'n seal 'em in with fiberglass, like most hulls are built,...

If ya go with Oak, White oak needs to be boiled before it's used to stop it from rottin' out so quickly...