The concordat between the Abbey-Principality and the American Chapter of the Order of the Crown of Thorns in the 1950s brought together Prince-Abbot Edmond I and Archbishop Lowell Paul Wadle in a resolve to work together for the common good and united future of the Order. As part of this agreement, the two prelates each gave and received a pectoral cross. Both crosses are now preserved as part of the Archive of the Abbey-Principality.

Jewelled gold pectoral cross presented by Archbishop Lowell Paul Wadle to Prince-Abbot Edmond I to mark the concordat with the American Chapter of the Order of the Crown of Thorns.

Silver pectoral cross presented by Prince-Abbot Edmond I to Archbishop Lowell Paul Wadle to mark the concordat with the American Chapter of the Order of the Crown of Thorns.