You might find descendants through a will for their youngest daughter Margaret who was bapt Andreas 8 Nov. 1855, and according to her M.I. died Oct.5 1928 ag.73.

She was the informant for her father's death
"Thomas Radcliffe, aged 83, Gardener, died 3 December 1878. Informant Margaret Radcliffe, Andreas Village".

Brian Lawson's will index ends in 1920, so you would need to ask at the General Registry, Douglas. Spinster aunts were often very good at naming nieces & nephews.

Sue