Looks like it was made in 1971 and yes the grips seem a bit strange like maybe they are new target grips instead of period correct ones. More pictures would help and it's a nice looking 15-3 and as far as value it depends on location a lot. The Model 15 is popular with Air Force guys because the Air force used them for the military police and for pilots and crews on some of their air frames. Clean ones not Air Force marked sell usually for $450 to $550 so we see what others say.