The very little we know about Julius Nepos's reign in Dalmatia comes primarily from the writings of Marcellinus comes and from fragments of the history of Malchus. Both are Byzantine sources. We know a little about his relations with the Emperor Zeno and Odovacer, but next to nothing about his rule in Dalmatia, except for his assassination. By this time, Nepos was hoping to retake Italy. Marcellinus comes suggested that the former emperor Glycerius (by now bishop of Salona) had a hand in the plot to kill the emperor. I'm not sure about the archaeology, but it would be difficult to date anything other than coins (and objects found with coins) to Julius Nepos's rather short reign.