1851 census has the family (Thomas Crebbin, wife Margaret and son William) at Crebbin House, Brada.
In 1861 William and his wife Margaret and young son William are at Ballafesson.
I believe that Margaret Gawne was the daughter of John Gawne & Jane Watterson of Ballafesson (chr 5 Aug 1798).
I don't know about 'Mr Gawne' the harbour master at Port Erin but if anybody does can they post and I might be able to place him.

Jane