So I used one of those Norton paint stripping wheels to clean the hull on my 1975 S300 Avon and it did a grand job. Went to the local hardware shop and bought a bottle of Toluene to clean hull before gluing. I ended up gluing on most of the Hypalon I bought but only 3 pin holes in the tubes the rest replacing old patches on the floor. I have reglued the transom timber which hard started to delaminate with a strong 2 pack resin. And also replaced all the A4 valve plugs.
Into day 2 of the hull remaining inflated without any apparent air loss. It is a rather good feeling when that happens as I bought the boat on a sense that it was a goodun' after seeing in crumpled up in the corner of a shed.
Next step is to rechristen her and get her wet and try out the old 25hp Evinrude that came with her. So far the motor has started first pull after initial fettling.
Fingers crossed.
Oh and happy new year.