Hello Sue and Trish.
Sue - Thanks for your advice regarding the Devon look Ups. I have put a request in. Trish - I agree with you that Wemyss is a Scottish surname.
His marriage certificate states he was born in New York, circa 1830, as does several of his childrens birth certificates. His death certificate states he was born in Devonshire, England. It was alleged that he came out to Australia in 1847 aboard the Joseph Soames, but there is no evidence of this on the passenger lists.
Rumours were that he was trying to run away or hide from something, but this has never been confirmed or proven, however appears likely.