The instrument in this entry is a very rare Martin 2½-40 guitar made before C. F. Martin & C0. was formed in August 1867. As such it has a "C. F. Martin" stamp on the back strip instead of the "C. F. Martin & Co." seen on guitars from late 1867.
Only four Martin 2½-40 guitars were made between 1854 and 1864, one in each of the years 1854, 1861, 1862 and 1864. This guitar is not the one made in 1854 as the ledger book notes the tuners were "German silver with ivory handles", and the tuner buttons on this guitar are pearl.
The records covering 1867 to 1884 were checked and no further 2½-40 guitars were made in those years, although a few more may have been made between 1885 and 1898. However, if any of these appear they will be simple to identify as they will have a "C. F. Martin & Co." stamp.
The tuners appear to be an early set of Seidel German silver machines.
Photos courtesy of Vintz Huang