Here's a fascinating piece, an F mandolin hand-built by Orville Gibson in 1906, well after the Gibson factory instruments were underway. Things to look for- scrolls everywhere. Orville's statement with this design of what he felt an F model gibson should look like after the factory changed the model? Look at the rounded careful carving, the degree of ornamentation, even down to little scrolls on the tailpiece cover!
Photographs of this mandolin were provided by Paul Hostetter, and taken by photographer Michael Darnton (both are builders of fine instruments themselves!)
George Gruhn wrote an article titled
Orville Gibson's last Mandolin that describes this wonderful piece in further detail