Here is a horizontal pair of Br. India 1865 2A SG 62 canceled in Kolamba, Shri Lanka.
(from my friend Arvind Rangaswami)
The stamps were on a cover from India to SL, which escaped cancelation at the dispatch post office, most likely located in a port city of Tamizhnadu viz., Chennai or Tuttukkudi and eventually canceled on arrival in SL.
Incidentally, 4A was the basic seamail postage from India to SL per 14.18gm (½oz), the rate in effect as follows.Feb 1,1856–Jul 31,1865
by Br. packetsAug 1,1865–Oct 1870
by Br./Fr. packets
During this period, 4A was the double rate i.e. for weight between 14.18gm (½oz) and 28.35gm (1oz) if sent by Indian packets.Oct 1870–May 1875
by Br. packetsMay 1875–Jul 1878
by Fr. packets