1922 'Arab Govt' violet h/s on 1920 opt 2Pi, perf 15x14, original opt type 1-1a se-tenant pr, the type 1a being a substituted cliche in only sm part of printing. VF fresh M. Sc 50(var), SG 42b/42ba cat £1560+ as singles, while se-tenant types pr should be at least +30% so est £2000++. Extremely rare multiple for specialist. BPA photo cert. (P)