I decided to try both options for repairing the rubbers and injected silkaflex into the leaking section as well as wolding it over the same section. I have added some photos to show what I did. So far everything seems to have worked out OK. I'll leave for another few days to make sure that there are not further leaks and then tidy up the work for a better finish.
Its not pretty but it works, no more leaks. My local Nissan dealer quoted $460.00 (supply only) Sikaflex cost $19.95.