Anne, is "biro" synonymous with "ball point pen" or is there some discernable difference in the inks used?
also, i agree with Christine that this label could have been placed by nearly anybody at any stage (manufacture, import, retail, etc.) in the early life of this piece. i believe the label itself is on par with those that are used in price guns today... nothing striking, really, to distinguish one from another.
if you're still curious about date/possible maker, a picture of the whole piece would be helpful.