My mother's maiden name is McLeaster. We've done some research on her family. We have come across many misspellings of the name as well. We have gone back as far as James McLeaster who lived in Pennsylvania, born in the 1770's? We believe he was born here in the US. We do not know which country our ancestors are from, the elder family members believe it is either Ireland or Scotland (of course the name kind of gives that away). Good luck.