There are also lists of Post Offices in 30 or 40 small British colonies, including locations and opening/closing dates, at:
http://www.pbbooks.com/cr1.htmHere is a very brief excerpt from the Jamaica list:
Albany Station 1904 18n17 76w50
Albert Town 1902 18n17 77w33
Alderton 1908 18n18 77w13
Alexandria 1859 A27 18n18 77w21
In each case, the last two entries are latitude and longitude.