I assume that you have any informaiton Imight provide but I can tell you a bit. In fact, if you can fill in any holes, I'd love to know.
Ferris lost the castle due to support for the Rebellion in 1641. He and his family were transported and the castle went to someone. I don't know who it went to immediately but I think it may have been a Lancelot Sandes. He may simply have gotten lands in the area, however, and not the castle. Sandes had fought with Cromwell (not in the earlier rebellion and I do not believe he was an "adventurer") and was almost certainly granted lands in 1666 for the reason of his service. I'm not sure that the lands Sandes received lands were from Turlough McOwen Ferris but I believe they were. The Sandes consolidated their holding a few years later out of Kerry. Who the lands transferred to could be significant but I do not know who that would be.
In one source I read, Francis Brewster received the castle in 1656, again, after the Ferris family was "transported". In any case, at some poing the castle was leased to Robert Eagar who came into the county from County Laois (Queen's County). By most sources, Brewster had the castle by 1677.
What I am most certain of is that, aroudnt he turn of the century, the castle and neighboring grounds were transferred in ownership to Eagar by Brewster who, I believe, was in Dublin at the time.
I'd love to know if this reflects what you know about that castle.
Good luck with your work,