Following on from this thread
https://www.vintage-radio.net/forum/...d.php?t=131102
the TV looked destined for the tip as the microprocessor was unavailable. The only possible source for the IC was on ebay from Italy at a cost of £30. As I was unsure if a replacement would come mask programmed it seemed too much of a gamble. Recently the IC became available from a UK supplier on ebay for £13 pounds so I bought one and it works!
I was wondering how the IC could suddenly become available. They had lots in stock. I guess it must be NOS but I would have thought the IC would have only been available direct from Zanussi being a custom part. Nice to have the set working again.