I took this photo at Gruhn Guitar in Nashville, TN. This is a 1923 Gibson F-5 Master Model with label signed by Gibson acoustic engineer Lloyd Loar dated July 9,1923 (same day as Bill Monroe’s mandolin). This is the most sought after mandolin model ever made by any manufacturer in the entire history of mandolin building. 1923 is the most sought after year (July 9 most sought day). Loar signed labels only from mid-1922 through December 1924.