More investigation this afternoon, I took the stern outer stem off to see how its assembled & look at the plank hood ends.
I had thought the planking was T&G but in fact it is all rebated along its edges, So the nails go through next to the rebate & this holds both planks onto the frame, compared to standard carvel its a 50% saving on nails.
More rotten ribs found, its quite bizarre with some that appear quite sound on the surface being soft & punky underneath or inside, its patchy here there & all over the place. I estimate i'm going to have to replace 90% if not all of them. Typical!
Those last 2 years sitting outside on the previous owners driveway have done her no favours at all.
There are 9 half ribs each end that stop at the apron then 48 full length ones that run all the way across. Several planks are soft under the ribs so there is some planking to do as well.
Fortunately i have a good stock of decent mahogany for planking. A bit of sanding & the planking comes up beautifully.
First job is to number & remove the bilge runners & armouring from the bottom. I am not sure what timber it is, its very pale straw colour & quite hard with very fine grain, It isn't Ash.