Where were Duncan McEwen and his wife Elizabeth Anderson McEwen born?

Question

All that I know about these two people are their names.  Though I believe that they were probably born in Scotland, since their son Peter McEwen was born in Perthshire, Scotland (1802).  -Peter died on October 2, 1869 after marrying Margaret Andrew (1796-1876) who was also born in Scotland.-

Peter and Margaret McEwen were the parents of Duncan McEwen (Perth, Scotland 1835-1892) who marrie Jane Margaret Andrew-McEwen (1840-1886).

Any information about Duncan or his wife Elizabeth would be greatly appreciated!  Thank you!