Most if not all of the Airtours 4B's went to Dan Air. Not all saw service, some airframes being used as a source of spares. The only surviving 4B is G-APYD at Wroughton but alas she was not part of the KT fleet.
Regarding memorabilia the OP may like to know that their is an aviation collectors fair at the K2 leisure centre in Crawley this Sunday (12Th of September) from 10.00 am. I am in no way connected to the event and I hope mention of it does not breech any posting rules.