The bell was sold in the late 19th C. to the British Museum by Marcus Kean of the Ballyvoe, Ennis, Co. Clare, branch of the KEAN family. I do not believe they were, at any time, formal custodians of the bell, but probably came into possession of it in the mid-19th C. when a FitzGerald widow gave it to that family. The FitzGerald family probably obtained following a marriage with the Kilrush KEAN(E)s who were for a while in the 16th C. "Co-Arbs of St. Senan".
Mrs. FitzGerald may have thought that the KEANs of Ennis were entitled to the bell, but they were not at all associated historically with it. They were related only by marriage to the Kilrush -Scattery Island- KEAN(E)family. This involved a Kean/Kean and a Kean/FitzGerald marriage of two sisters ca. 1720-30. Otherwise Mrs. FitzGerald perhaps gave it to the KEANs of Ennis bacause that family included a well-known local antiquarian.
Recently I have heard that there are efforts underway in Co. Clare to retrieve the bell for local custody.