In Search Of
was great for its time. Granted, it rehashed a lot of popular mysteries, the usual fare of tabloids such as UFOs, Bigfoot, the Loch Ness Monster and others, but it also delved into a lot of lesser known topics as well (such as the Money Pit).
I know a little bit about the making of that particular show, as I've corresponded with D'Arcy O'Connor, who was involved with the production. Filming and recreation of historical scenes were filmed in Nova Scotia on the mainland, and shots of the island were taken from the air. Leonard did the narration in Los Angeles after the footage was assembled. I don't think that he ever visited any of the locations used in the show, to the best of my knowledge.