Someone with better knowledge than me will know for sure... But my recollection is that these were the only "metallic" labels on the Proton Pack:
(On some Proton Pack props, this label was a red vinyl label rather than a silver one)
And the only "metallic" labels on the Proton Gun:
(Between the two round dials)
Though in truth, "metallic" is a subjective discription - some labels were printed on metal (the red circular one), some were metallic foil (potentially the Clippard valves and red rectangular label), and some may have been printed onto a shiny vinyl (potentially the small rectangular labels).