guess you know that the JMO = Joyce Oates and presumeably you took it verbatim from Manxnotebook

I have a bit more re family but havn't got round to collating it - the link to the 'royal's would appear to be one of Canon Quine's sallies (possibly like his suggestion that the Island saw Roman occupation!) in linking the last (or possibly penultimate depending on source) Abbot of Rushen with the Thomas Ratcliffe who is briefly entered for Knockaloe in 1540's (then a long gap before name reappears) - as Sue says much unverified material- much of which is obviously wrong out on net.
If you borrow film of 1643 composition book (tho I think the entries date 1647 onwards there are a few hints:
1643 composition
Thomas Radcliffe houlds ye 4th pt of a qtr of land
certain prcells of intacks and a prcell of cottage
for 3 lives that [] 1 life for sd thomas
and of thomas his son and of Isabella
his daughter paid fine 10s 6d wch []
11s 3d all ye lives yet in being granted ?
1647
...
Thomas Ratcliffe of Knockallow holdeth the fishinge of the
bay at the Peele for salmon and all other fish for the
terme of 21 years and payd rent £3 4s and
granted 1643 as appears under the Earl of Darbye hand

Samsbury Ratcliff houlds one quarter of
land scituat in K Patrick and one
water corn milne scituate in k german
for 3 lives vizt for the life of thf the Salsby
Ratcliffe and of Henry Radcliffe brothr
of the said Sanbry Ratcliff and of Henry
Ratcliffe son of the sd Sambry paid for
by Elizabeth Ratcliffe alis Holland ?
the rent re[]ed and paid £3 6s 9d all ye
lives in beinge & reserving the right of
the sd Elizabeth accordinge to certain aggremt
between the sd Sambry and the said Elizabeth
his mother concluded upon.

[German] - quite a bit further in book - suspect might be a year or so later + possibly same mill - the 1/3 looks af if mother died ? and divided among children

Henry Ratcliffe houldes ye 4th pt
of a qtr land and the 3rd prte of a
mill and certain other prclls of
Intack for 3 lives that is to say for ye life
of himself and of Thomas his brother
and Edmund Quaile son of thomas
quaile 2 lives yet in being pd fine
£1 7s 6d 5d? rent reserved and only ?
pd 16s 2d granted in 1643

in 1637 presentments:
Examinacons taken before ye Ordinarie & ParsonTompson & Vicar Cannell, Mar: 10. 1637, at Bps Court:
Jane Ratclife als ffargar sworne & examined saith yt Eliz: Cosnahan said unto her by way of disgrace, was not thy grandmother a witch? for wch shee was censured, for yt imputacon & asked forgivnes. Lykewyse this examinate saith upon oath yt ye said Eliz: Cosnahan called her father a leprous knave his mother a whore, herselfe a whore, & yt shee was Carted in London. These things were spoken some 10 or 11 years ago. [See Archd will 1663 #106 German of William Radcliffe (& Jeane/Jane Faraghar his wife), dated 1 February 1663/4 at top: Henry Brokfeild, kinsman Mr. Thomas Ratcliffe of Knockabie[?or Knockalie or Knockaloe?]; friend Henry Ratcliffe of Peeltown; brother Charles Ratcliffe
[Wm & Jane apparently died within a short time of each other]]

also in 1637 presentments
Tho Quail aged 60 yeares or yer abouts sworne & examined saith yt he ever knew knockaloe Cotters pay there small tythes in kinde & yer tyth fish & further saith yt Thomas Craine tould him yt ye Vicr his father had every year from ye wife of Knockaloe a new coate & ye -------- of his goods without molestation upon yer land continually wch he conceaids[?] was given for not questioning them for there tyth corne & further cannot depose. Also sayth that Gourdan tyth was pd in kind before Gilbt Calow death & since set to Henry Ratliffe for severall leases[?]. Thomas Quaile.
[Henry is set for a lease of Gordon in 1610 of 19yrs - stated that he held previous by lease thus looks as if acquired lease in late 16th C

the Archdeacon Will 1675 #92 Braddan of Christian Quayle als Radcliffe als Kissage, widow of BallaQuayle, died 12 February 1675-6:gives details of sylvester radcliffe - son capt thos

Archdeacon Will 1659 #1 Patrick of Christian Jane als Kegg: husband alive; Thomas Ratcliffe & his son Silvester Ratcliffe; dau Katherin (if she has no children, then her legacy to return to Xtn’s husb & Tho Ratcliffe);