J6ac, J6a (D9a, D9) 1929 18¢ black on salmon Postage Due typeset, rouletted 10, VARIETY - "cent.s" for "cents.", only occurred once per sheet of 10 (row 4, pos 1) of the initial printing, unwmkd, scarce, vertical pair with normal, tied to piece by "Zanzibar" cds.
