I have set leather into the sections of the seat that are not perfect. This has helped so the idea of resin seems excellent.

I will use the boat as it is to assess it on the water and make my descisions then.
I may however glue the beams in with a product called MS ALL here in NZ. It is a super silicon glue/sealant which I have used on other beams with great success. If you really need to get the beam off you can slip and long razor sharp blade in. A ball ache and it takes a long time but the boats are not degraded by it.

Thank you so much for the fixes, they are copied into my H17 file and will be put to good use.