Regarding point 3 above VIRBONUS is an attested early Christian name A quick google yielded the following examples A bishop named Saint Virbonus who attended the Roman Council of 595 Source D Pringle A group of medieval towers in Tuscania in Papers of the British school at Rome Vol 42 1974 pp 179 223 A Roman abbot named Virbonus ca 650 Source E Wellesz Recent studies in western Chant in Musical Quarterly Vol 41 no 2 April 1955 pp 177 90 I note that the Thetford treasure also has the inscription VIRBONE VIVAS Given that all the other dedications are to persons it seems more likely that this one is likewise rather than the vague dedication good man