According to the Omega Archives, the present watch was delivered to Japan on 30th April 1962.
This excellent example is from the second generation of OMEGA “pre-professional” Speedmasters, ref. 2998, successor of the reference 2915. It began its production in 1959, eight case references (-1, -2, -3, -4, -5, -6, -61, and -62) were successively introduced during only four years. Notably, this reference was the first OMEGA to ever travel to space, as worn by astronaut Walter "Wally" Schirra as his personal watch on the Mercury-Atlas 8 mission of NASA's Mercury program in 1962. A rare find, this watch is made particularly desirable as it is preserved in good condition and maintains a handsome aesthetic with original unrestored dial and tropicalized bezel faded to a silvery grey.
An example of the reference 2998 is illustrated and described in OMEGA, A Journey Through Time by Marco Richon, 2007, p. 598.