Svengoolie: Mysterious Island (1961)

 

Directed by Cy Endfield.

https://en.wikipedia.org/wiki/Mysterious_Island_(1961_film)

https://trailersfromhell.com/mysterious-island-encore-edition/

https://www.tcm.com/tcmdb/title/16895/mysterious-island#articles-reviews?articleId=28071

http://www.1000misspenthours.com/reviews/reviewsh-m/mysteriousisland1961.htm