Sir Paul McCartney jovially settling a long-standing ‘debt’ over a blanket is going up for auction.The letter was written in September 1989 in response to Irene Brierley, whose farmhouse in Harlech, north Wales McCartney and his late Beatles bandmate George Harrison stayed in during two occasions in 1958 and 1959 when they went on a pair of hitchhiking holidays.McCartney and Harrison became friendly with Irene’s son John during their first stay in 1958, with John recalling, as the Beatles