These links might help you narrow the timeframe for the beginning of Le Galion Hotel… (there’s more island history/info on this somewhat dated website for those interested.)
http://www.stmartin-sxm.com/sxm/pages/orient-beach-pre-1980.php
http://www.stmartin-sxm.com/sxm/pages/baie-lrsquoembouchure.php
http://www.stmartin-sxm.com/sxm/pages/pedro-s.php