BETWEEN 1968 and 1971, the late Dave Sexton, Chelsea’s softly-spoken and erudite manager,  received a string of letters – written with a duck-egg green Osmiroid pen – that highlighted the skills and attributes of a midfielder plying his trade with Manchester City. The young lad who wrote these testimonials was giving Sexton the benefit of his 10 years on the planet, his three years of watching grainy Match of the Day programmes, and his desire to bring top-class talent to Stamford Bridge.  This lad, whose first football kit was not in Chelsea blue – that would come later – but all white, the colours of Leeds United and Real Madrid, wanted to create the All Stars for Chelsea. Dear Mr. Sexton, I would like…