The commonly claimed '1st pressing' is an EMI-pressed record with 2U/2U matrixes in a laminated E.J. Day cover. That is, in fact, a second pressing.
The first pressing was not pressed by EMI and it came in a laminated cover printed by Robor which has a 'pinched' spine top and bottom. It was organised by Branson at the Lyntone pressing plant in Holloway, North London. (Although Lyntone is often associated with flexi-discs it was a well-established record pressing plant specialising in short-runs). These original pressings do not have the familiar stamped matrixes, mothers and stampers associated with EMI-pressed records. They have a simple, hand etched matrix number with no number suffix (and no mother or stamper information).
This is one of the earliest promotional copies which were pressed privately and financed by Richard Branson.
Note: In a later reissue of Tubular Bells (Green/Red label) also appears Printed in England by Robor Lyntone.