I now have the rings !!!! I got a call out of the blue last Thursday from Alfa to say the rings had arrived (almost two weeks ahead of schedule). I'll have the bottom end built up before the week is out.
I believe that most garages would have only replaced the conrod, rings & end bearings for number one cylinder on my engine. I thought it good form to replace the rings and end bearings for the other three cylinders as well given that I've stipped the engine. The engine has only done 51k so will be back to 'running in' condition when I've finished. A new cam variator is going in as well.
I'm even thinking of selling the car once it's back on the road.