My 1970 has no vents, 2 hatches forward and the scuppers drain down and then out the Transom. The 71 and on scuppers drain thru the floor. The 1969 scuppers drained thru the transom but slightly different than the 1970 setup (see stricks boat...his is a good example of the 1969). Stringers also changed from 4 to 2 in 74(ish). Also in 74 an in floor livewell and underdeck tank were standard(?). Non skid pattern changed in 74 ish too. Your non skid pattern is the same as mine. Confused Yet?