The 12-digit HIN was not required until 1972 (November 1, 1972, so really 1973 and later models). I'm not sure what that number is that is molded into the bow, 9475 is too low to be the O'DAY Hull# and too high to be the Widgeon Class# if this boat is a 1967 model. My old 1969 Widgeon was Hull# 22698 and Class# 1791. On the Widgeon the plate mentioned by ruidh was mounted to the aft side of the bow seat/flotation tank, it sounds like yours is missing? (Mine was falling off when I bought my boat, I reattached it with pop-rivets)
I think that your boat is a lot older than 1967, I'd say more like 1963. I base that on the way that you have a single horn-cleat on hte CB trunk for the Jibsheets instead of the later set of 2 cam-cleats and the way the mainsheet block is attached to the CB trunk. Later boats also had a fiberglass "cap" over the top of the CB trunk with molde-in spots for the mainsheet block and the jibsheet camcleats. So, it may be that your boat is a 1963 model (first year for the Widgeon!) and that the Hull# is 9475 and Class# is 86 (9475th O'DAY built and 86th Widgeon) WOW!! She looks pretty sharp for a boat of the vintage!
One tip, the jibsheets will work better if you run then inside the shrouds, that was how they were rigged originally with the bullseye fairleads mounted to the inside of the deck edge.
I've added a couple of pics of my little gem, and a page from the 1966 manual. The picture showing hte sail# (Class#) was after I bought a new sail.
