The study did not locate any covers canceled at either location, nor did it include cover addressed to either place. 

St.Jan had a 1901 census of 925 people, with perhaps 10 percent literacy, so little mail passed through that island. In Engstroms book illustrates the only cover known to have been canceled there  - March 27.

Kingshill was a different matter in that it did not cancel any mail from the late 1870s to about 1909. Kingshill is not a town and even today it is not identified on St.Croix maps.