Ceylon SG26 1861-64 1s slate-violet Perf 14-15.5 Mint Block Cat 900 as singles

Ceylon 1861-64 1s slate-violet Watermark star intermediate perforations 14 to 15.5 SG26. A fine mint block of 6 (3×2) with marginal watermark at top and fresh original gum (lower row unmounted mint). Minor separation between 1st and 2nd stamps but remains a rare and lovely quality multiple. Last sold by Stanley Gibbons in 2016 for 1400 pounds. A RARE Block