The articles I managed to find and a few extras. 
The Literary Digest (22 May 1937), pp. 25-27
The Listener (5 June 1935), p. 983
Anonymous review of Captain Kidd and His Skeleton Island:
The Listener (19 June 1935), p. 1065
Letter response by Harold T. Wilkins to 5 June 1935 anonymous review of Captain Kidd and His Skeleton Island:
Response to Wilkins letter by the anonymous reviewer:
Wilkins again responded on 3 July 1935.
I do not yet have the full letter but here are some snippets:
Pirate Treasure (1937)
Wilkins published a condensed version of Pirate Treasure in the magazine Short Stories 160 (4), [1937] pp. 153-172:
"The Money Pit" by Parker Morell in The Saturday Evening Post (1939):
A photo of Elizabeth Dick aboard the La Morna from a French publication.
I am still looking for access to read -
Naval Review (London), vol. 23 (1935):
Harold T. Wilkins, "Captain Kidd's Treasure", The Passing Show May 6 (1933) v2 #59, pp. 5-6:
Harold T. Wilkins, "Captain Kidd and his Treasure Island", December 1936 in The Scottish Field.

The Literary Digest (22 May 1937), pp. 25-27
The Listener (5 June 1935), p. 983
Anonymous review of Captain Kidd and His Skeleton Island:
The Listener (19 June 1935), p. 1065
Letter response by Harold T. Wilkins to 5 June 1935 anonymous review of Captain Kidd and His Skeleton Island:
Response to Wilkins letter by the anonymous reviewer:
Wilkins again responded on 3 July 1935.
I do not yet have the full letter but here are some snippets:
Pirate Treasure (1937)
Wilkins published a condensed version of Pirate Treasure in the magazine Short Stories 160 (4), [1937] pp. 153-172:
Short Stories v160 n04 [1937-08-25] : Free Download, Borrow, and Streaming : Internet Archive
Pulp Fiction Magazine
archive.org
"The Money Pit" by Parker Morell in The Saturday Evening Post (1939):
A photo of Elizabeth Dick aboard the La Morna from a French publication.
I am still looking for access to read -
Naval Review (London), vol. 23 (1935):
Harold T. Wilkins, "Captain Kidd's Treasure", The Passing Show May 6 (1933) v2 #59, pp. 5-6:
Harold T. Wilkins, "Captain Kidd and his Treasure Island", December 1936 in The Scottish Field.
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I think it is likely between 1940 and 1947 he published another article on the maps.