Thanks guys, again! Lots of constructive ideas and suggestions (a great example of how valuable and respected this forum is!).
I'm considering options; I have an independent (but not Alfa specialist) providing me with some very good quotes and based on the quality of their alround knowledge of rebuilding engines (as well as a close personal contact) I'm interested in their proposition.
I think on the balance of it I need to get some clarity with Alfa Romeo direct and plan to contact Head Office tomorrow. It's interesting to see/read that even on a forum like this, with dedicated Alfisti, there is some uncertainty about the requirement for cambelt change.
Certainly I feel quite frustrated at the fact that the last service, which was significant, I wasn't informed clearly about the requirement for the replacement. I'd fully expect, on their specific advice, that I could safely make it through to the end of this year.
If the car was used and abused I would expect less sympathy but I've worked hard to keep this Alfa in tip-top condition and placed my trust in a main dealer; so I'm hoping they are as good as their word and can show that they do indeed care about their community.
Again, many thanks for all your contributions and support guys!