Labels and Markings
L-5s built prior to December 1924 had both Gibson ‘Master Model’ and Lloyd Loar signature labels (the latter signed and dated by Loar himself). Lloyd Loar left Gibson in December 1924 and the last Loar-signed label appeared in that month. 1927 was the last year for the ‘Master Model’ label.
‘Master Model’ label, 1922 to 1927
The model designation and serial number were written by hand.
Lloyd Loar Signature label, June 1st 1922 to December 21st 1924
In addition to the ‘Master Model’ label, a label signed and dated by Lloyd Loar was fitted. It reads: ‘The top, back, tone bars and air chamber of this instrument were tested, tuned and the assembled instrument tried and approved – followed by the date and Lloyd Loar’s signature – Acoustical Engineer.’ (Loar’s signature and the date were written by hand).
White oval label, c. 1908 to 1932
‘Gibson Mandolin-Guitar Co.’, 1898 and 1906 patent notices (unlike earlier labels, this has no photo of Orville Gibson). Both the serial number and the model name were hand inked or pencilled (from 1917 the model name was ink-stamped on some examples).
Instruments shipped from 1933 have a white oval label with ‘Gibson Inc.’, in typeset lettering (no Mandolin-Guitar Co.). The serial number and model name were now inked stamped.
Made in the USA stamp
From the late 1920s to the 1950s ‘MADE IN USA’ was impressed into the back of headstock of examples intended for export.
The Factory Order Number (FON)
From the start Gibson used a factory order numbers (FONs) to track production costs and control inventory. All pre-war Gibson instruments were assigned an FON, though this doesn’t always appear on the instrument. The FON is the best indicator of when the instrument was manufactured while the serial number relates to its shipping date. In the case of L-5s and other high-end archtops, the FON is visible through the treble side f-hole. Note that in the case of Loar signed L-5s no FON is visible (the FON may have been written on the guitar’s interior back and later covered by the label bearing Loar’s signature, as was the case with the Master Model mandolin family instruments).