Dermot, yes I think that the Crosbie dynasty are the most likely culprits to be landlords for most of the O'Dorny area.
O'DORNEY, otherwise called Kyrie Eleison, an abbey under the invocation of the Virgin Mary was founded in 1154, for Cistertian monks. Its possessions, formerly very extensive, were at the dissolution granted by Hen. VIII. to Edmond, Lord of Kerry, created Baron O'Dorney in 1537. In 1596, the abbey was granted by Queen Elizabeth to the Provost and Fellows of Trinity College, Dublin; and in 1603 the rectory of O'Dorney was granted by the Queen to Wm. Taaffe, Esq.: it is now the property of W. Talbot Crosbie, Esq., of Ardfert Abbey. The parish comprises 10,140 statute acres, as applotted under the tithe act, and valued at £5236 per annum. The living is an impropriate cure, in the diocese of Ardfert and Aghadoe, and in the patronage of Mr. Crosbie, who receives the tithes, amounting to £184; he has appointed a curate, and a church and school-house are about to be built.
From Thom's Almanac and Official Directory for the Year 1862.
Deputy Lieutenants. Crosbie, Major James, Ballyheigue Castle, Ballyheigue; Kildare st Club, Dublin; Union Club, London, S. W.
Crosbie, William Talbot, Ardfert Abbey, Ardfert.
Magistrates. Crosbie, Major James, D. L., Ballyheigue Castle, Ballyheigue; Kildare street Club, Dublin; Union Club, London, S. W.
Crosbie, Wm, Talbot, D. L., Ardfert Abbey, Ardfert.
County Officers. Clerk of the Peace, F. Crosbie,esq. (1819), Ballyard, Tralee..
Maurice Crosbie, 1st Baron Branden was born circa 1689. He was the son of David Crosbie and Jane Hamilton.1 He married Lady Elizabeth Anne FitzMaurice, daughter of Thomas FitzMaurice, 1st Earl of Kerry and Anne Petty, in December 1712 . He died on 13 January 1762 He was buried at Ardfert, County Kerry, Ireland. He held the office of Member of Parliament (M.P.) for County Kerry between 1713 and 1758.
You can see that the Crosbie landed gentry enjoyed the income from their 10,000 acres for several centuries, and it is probable that some of their tenants held "lifetime leases" for 60 years, that were transferable to the tenant farmer's heirs, so land occupation of 300 years is quite possible.
See my personal message to you (we can discuss this by email).