¹Ireland, Aideen M. "Roger Chambers Walker: A Sligo Antiquarian." The Journal of Irish Archaeology 11 (2002): 152+.

²Ireland 150.
The author quotes William Stokes reporting that Petrie was a "guest at the neighbouring house of Rathcarrick, the residence of Mr Walker, a gentleman endeared to him by old friendship, by the fascination of his manners, and his fondness for antiquarian pursuits." (Stokes, William. The Life and Labours in Art and Archæology, of George Petrie ... London: Longmans, Green, &, 1868. 240.)

³Ireland 156.

⁴Wakeman, W. F., and James Mills. A Survey of the Antiquarian Remains on the Island of Inismurray. London: Williams & Norgate, 1893. v.
From the preface by James Mills.

⁵Ireland 155.

⁶O'Sullivan, Jerry, and Tomás Ó Carragáin. Inishmurray: Monks and Pilgrims in an Atlantic Landscape. Cork: Collins, 2008. 27.

⁷Heraughty, Patrick. Inishmurray: Ancient Monastic Island. Dublin: O'Brien, 1982. 38.
According to Cormac Bourke, "Walker's ownership of the crozier and bell from Inishmurray is confirmed by an unpublished letter of 28 October 1843 from Petrie to Lord Adare (later the third Earl of Dunraven)." (Burke, Cormac. "A Crozier and Bell from Inishmurray and Their Place in Ninth-Century Irish Archaeology." Proceedings of the Royal Irish Academy. Section C: Archaeology, Celtic Studies, History, Linguistics, Literature 85C (1985): 146.)

⁸Burke, Cormac. "A Crozier and Bell from Inishmurray and Their Place in Ninth-Century Irish Archaeology." Proceedings of the Royal Irish Academy. Section C: Archaeology, Celtic Studies, History, Linguistics, Literature 85C (1985): 145-68.

⁹Ireland 156.
Some of the Walker/Nothumberland objects in the National Museum of Ireland were purchased by the State from Sotheby's London in December 1990, from the trustees of the will of the 10th Duke of Northumberland. The Walker collection was originally purchased for Alnwick Castle by Algernon Percy, 4th Duke of Northumberland, who in 1852 was named First Lord of the Admiralty.
Aideen Ireland quotes from an editorial in The Dublin Saturday Magazine highly critical of the deceased antiquarian: "The late R .C. Walker who, in search of antiquities, had opened more ancient tombs than any other person of modem times in this country, possessed an almost unique museum of Pagan and early Christian works of art and art manufacture, relics of the various races which had ruled in Ireland from pre-historic times. His entire collection was sold by his executor to the late Duke of Northumberland. Where is it now? And yet Mr Walker received, as presents from friends, very many of his best specimens on the clear understanding that he collected only for national and patriotic purposes, and that no portion of the contents of his museum, should ever be allowed to leave Ireland. Many other instances of the wholesale exportation of Irish antiquities might be referred to; and we regret to say that a regular traffic in such articles with English curiosity-seekers is to this day carried on by well-to-do and even professional men who would scorn to be styled tradesmen, but who act like peddlers in their greediness for a miserable profit, and like rogues, in procuring antiquities from patriotic sellers at a cheap rate, under the pretence that they are gentlemen, who only collect such matters through love for fatherland." (The Dublin Saturday Magazine ii, no. 43, [1865-7], 250.)

¹⁰Ireland 173.
The author lists the following from "A Descriptive Catalogue of Antiquities chiefly British at Alnwick Castle:" "Page 183 no. 886 Part of staff- St Molasse (Walker?); Page 188 no. 913 Iron bell of St Molasse (Abel?)" Note that the decorated cursing stone, in all probability also from Inishmurray, is not listed as such in the catalogue, nor was it included with the repatriated artifacts.
It seems that just one year after the purchase of the Walker collection, the Duke of Northumberland donated some of them back to the Royal Irish Academy. A report from the Academy's records of November 1852 states: "The Lord Chief Baron in putting the motion said that their thanks were especially due to the Duke of Northumberland and all other persons who finding articles of more interest to others than to themselves, send them forward to their proper homes, where their value would be duly appreciated." (153-54).

Photos: The image of the two relics from Inishmurray is after Ross Trench-Jellicoe and is from O'Sullivan, Jerry, and Tomás Ó Carragáin. Inishmurray: Monks and Pilgrims in an Atlantic Landscape. Cork: Collins, 2008. Also from that text is the photo (National Museum of Ireland) of the wooden statue of St. Molaise. The drawing of the crozier, as well as the detail photograph of its crest, are from Burke, Cormac. "A Crozier and Bell from Inishmurray and Their Place in Ninth-Century Irish Archaeology." Proceedings of the Royal Irish Academy. Section C: Archaeology, Celtic Studies, History, Linguistics, Literature 85C (1985).