Pakistan SG38 and 40 Salimullah Hostel 1r and 5r in IMPERFORATE U/M blocks

1948 (-57) type 12 Salimullah Hostel Dacca 1r ultramarine and 5r carmine each in an IMPERFORATE marginal block of 4 unmounted o.g. The 1r with archival mounting in margin and tiny tone specks on gum but very fine appearance. (The 2r value is not known to exist in this form.). Original Purchased from Stanley Gibbons (Still on their card)