Thank You!Probably 1978.
Thank You!Dash ones ran from 1960 to 1987. That's a long run for a dash model, IMO.
S/N runs from 1969-1971, more likely 1969.
Hope this helps.
Thank You for nailing it down.Serial numbers used from 1978 - 1979 started at M100000 and ended at M130000. As JP@AK stated, your 34-1 serial # M103xxx very likely came from 1978. The M prefix serial numbers were used on Models 34, 35, 43, 51 and 63.