First thing is that she is not a 1968, the MARINER 2+2 was introduced as a 1969 model, so....one bit of "good" news, she is at least a year NEWER than you thought! Looking at the O'DAY Hull# I'd say she is an early 1969, built early in 1969 as opposed to later, my 1969 Widgeon was O'DAY Hull# 22698 and must have been built in mid-to late 1969.