Registered cover franked with 1930 single ½d black & green and block of four 2d slate grey & lilac 'OFFICIAL / OFFISIEEL' overprint issue (SG O12 & O14) tied by multiple strikes of OBSERVATORY cds dated 23 JAN 1931 with boxed 'OBSERVATORY' registration marking in purple alongside. Addressed to AUSTRIA with transit & arrival marks on reverse. Cover is slightly trimmed at top and bottom.