Danish West Indies
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 "Danish West Indies Mails" there is a photo of the only known cover with a bisect to have been canceled on St. Jan - March 27. Below is a photo of the only known cover with a bisect addressed to St. Jan - having been backstamped St. Jan upon arrival.
Kingshill was a different story - 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.