I have come back to the start of this enquiry, reason being I had simular situation years ago, and funny enough I have another one.

Have you tried the G.R.O. Registry Office , in Southport. England. If you enter this into www.google.com or "ONS" " Office of National Statistics" . I know they will not have any Manx records , but England and Wales they will have. Give them a ring or email. "You just never know"

Good luck

Brian ..... www.kneen.com