Okay, assuming that the Wm Vondy living in Dale Street, Ramsey in 1841 was 74 years old, then he was born c1767. There is a christening record for a William VAUNDY son of Thomas VAUNDY and ANN GERMEEN (surely 'Kermeen'). This William was christened on 22 Nov 1767. He fits the bill, and fits even better in my tree starting from Wm Vondy & Cath Kewen.

Anybody out there got a list of children for Wm VAUNDY/VONDY and Ann Kermeen?

Time I started putting this all onto Family Tree Maker or something!