Just out of interest, I think this is the same model that Simon Nicol of Fairport Convention has played for years; he's tried lots of 12s, but won't swap this one for anything.
According to the Fender product dating site,it was made between 1972 and 1980, imported from Asia. The same site states that the serial numbers for these guitars were never archived, so it is not possible to date them precisely. Having said that, given the volumes of these guitars produced, a serial number of 975 suggests an early one.
Hope this helps a bit.
Tim