Wow, thanks for the responses guys (I'm assuming you're all guys, not that it matters). I really appreciate it and I think given the suggestions, apart from maybe taking the flywheel off to blob some oil on the flywheel cam as suggested, I'm not going to touch it until it stops working.
I know I could have gone for a smaller engine but went for as large as I could on the basis that it would be quieter and more relaxing to have a larger engine running at lower revs, than a small one running flat out.
I found this link written by Nos and kinda wish I'd come across it before I bought by current gear:
Buying Used Outboard Guide- World Sea Fishing Forums | Sea Angling and Sea Fishing Online | Fishing Reports
However I have it now so am trying to make the best of it. I love the fact that I have a retro engine, I just hope its not so retro that it doesn't work. It's a lottery but you can be sure I'll take some photo's and post them later in the year.
I will definitely be taking oars and paddles.
Thanks again
Adie