The player who brought this guitar into the shop tells me, “I bought it from a guy who said he bought it second hand back in the 1940’s.  I’m told a lady sat on it at some time in the past.” And from there, the mystery unfolds.  Measuring the box tells us it’s most likely the model L-50 made after 1934, models before that time had an oval sound hole, where ours features f-holes. Gibson wasn’t using serial numbers consistently at this time, but they did use a system called Factory Order Numbers, which were stamped on the back plate visible through the treble-side f-hole.  Our FON is likely 2138.…