Sandra - you may be interested in some digging I did some years ago. The Knockaloe Radcliffes seem to descend from Thomas Radcleff who was the Lord's Receiver at Peel Castle in 1535 and 1543. He would have been a trusted associate or tenant of the Stanley family from their Lancashire heartland. He acquired extensive property in Patrick, Lezayre and Douglas in the 1550's. died before 1576. He married Margaret Holland (alive 1594) & had at least 2 sons, William R., Waterbailiff inherited Knockaloe, and Henry R. , Deemster (1593-1626) acquired Gordon, Patrick before 1603.
As to Andreas, a John Raydcliff held Ballaradcliffe from at least 1575, paying 18 shillings rent for the same. Unless there is a will for Thomas or Margaret in the unfilmed wills from the 1570's, we are at a loss as to whether John was of the Knockaloe family, or came in separately.

Cheers
My descent is from Thomas Radcliff of Glen Maye, first entered for 5s 3d rent in 1603. William of Knockaloe had a son Thomas by his second marriage, who may be my ancestor.