The international Salvation Army Centenary was commemorated on these UK stamps. Between 1962 – 67, UK stamps were printed with & without phosphor bands (ref.: Bradbury catalogue). Covers with both sets of stamps are rare. I’m a bit uncertain about cat. value, but have seen £60 mentioned (combined value of FDC with & without phosphor; £25 + £35).  Estimated value (expected salesprice on Ebay) is £25 – £30 and probably much more if the cachet is rare.