Dan Air did have Yorks; they used to operate ITs out of Luton early '60s having been 'evicted' from Blackbushe when the government closed it as an MTCA airport in May 1960 to try to force independent airlines to move to Gatwick, which had a much worse weather record.
Last one I saw was at Lasham in about '66. Dan Air operated the maintenance base there in those days; the York was originally intended to be used as an HQ for the Air Scouts but when I saw it was parked at the maintenance area along with an Ambassador.