This was brought to me by a former customer. I had done some work previously on his electric bass. He mentioned he had an old Gibson mandolin that didn't stay in tune and was worried the tuning machines needed replaced.
I was overjoyed when I opened the case. It was in great condition and appeared to be all original with the exception of a missing tailpiece cover. I set about fixing the detaching binding first.
Nothing a little cyano glue and some rubber bands can't fix!
Cleanup required just a little scraping of the fingerboard and some ultra fine steel wool against the binding to get rid of any glue residue.
While the strings were off I cleaned and polished the whole instrument and went about trying to date it. I could tell it was a pre-war instrument from the script logo on the headstock and the old fashioned "guarantee" label inside.
At the time of the paper label, the serial numbers were written in pencil. That of course has faded decades ago, but the ghost of the number can still be made out if held at the precise angle in the right lighting. 36994. The lack of a letter before the number places it on or before 1947, and according to Gibson's records, the last serial number in 1916 was 3200, and the last serial number in 1917 was 39500, which dates this mandolin to 1917.
Luckily for everyone, the tuning machines are in perfect working order (worm and pinion design with quality metallurgy is hard to fail) and all it needed was some new strings and precise intonation. Now it's playing great and will hopefully continue to for another 98 years.