Sounds like he was looking for a stereotypical "barbarian" vest. I dont think it was very common to cover mail with anything at that time...mail was a status symbol...you wanted to show it off.
I think the leather jerkin adorned with metal studs might have been handed down to us by Kirk Douglas' The Vikings and perpetuated by folks like Museum Replicas Ltd (who now seem to have "retired" theirs from their offerings). It's a fun, flashy garment to be sure, and one that appeals to our love of those sword and sandal fims of the 40's and 50's (?). We are tempted to want to believe 'Vikings" wore such "manly" gear. But sadly, it seems instead to be the stuff of Hollywood (and Elstree) costumers---like horned helmets and steel-cupped Valkyrie brassiers.