I have on my desk at this moment a Sunshine Unlimited Mark 4 Fretboard Stamp (The original since 1989) from what looks like Panorama City Calif.91412Try Elderly Instruments or the Twelfth Fret in Canada although it would seem to me any decent sized music store should have one. It has stamps for guitar banjo bass and mandolin and a stamp pad in the lid of the container.
Michael Miland