Thanks, Phil.

We are not having much success finding the other members of Alex & Cath's family, nor what happened to Cath after Alexander's death.

Only this, possibly for John:
John RADCLIFFE bapt.7 DEC 1823 Andreas?
1851 Douglas, 5, Cambrian Place
John RADCLIFFE Head Married 26 labourer Andreas
Elizabeth RADCLIFFE Wife Married 26 Onchan
William RADCLIFFE Son 4 Douglas
John RADCLIFFE Son 1 Douglas

In 1861, Lonan, 24 Laxey Glen:
John RADCLIFF Head Married 39 Labourer Andreas
Elizabeth RADCLIFF Wife Married 35 Onchan MAXWELL [marr.Onchan 1843]
William RADCLIFF Son 14 Mine Labourer Douglas
John RADCLIFF Son 9 Mine Labourer Douglas
Elizabeth RADCLIFF Daughter 5 Scholar Douglas

Sue