Kjeld, I used the Avon 215-60-15 but used 275-55-15 for the rear as they are closer to the exact measurments of the original Arriva tires. They look and fit perfect and the only issue was they are very sticky rubber which does throw up a lot of stones and debris depending on the road conditions.
Here is a link with photos of the tires on a car that I sold at RM a while ago.
https://rmsothebys.com/en/auct...era-l-by-ghia/545607
Good luck, Glenn