1d Black (plate 9). On entire from Spilsby to Lincoln cancelled by a neat black Maltese Cross with another fine strike at left. Double strikes of the Maltese Cross were a peculiarity of the Spilsby P.O. Reverse with dispatch and arrival marks for AP. 1/2 1841. Alford, Burgh and Spilsby (all in Lincs) had a curious practice of applying a second Maltese Cross alongside.

Rockoff and Jackson Vol 2, page 253.