Where did you get that list of Widgeon sail numbers cross-referenced to the build years? That would be a SUPER GREAT addition to the Expanded Owners Manual that I created and sell copies of! It also confirms (if accurate?) my recent discovery that my Widgeon (Hull# 22691, Class# 17910 was a 1970 model, not a 1969 model as I had always thought.
I will tell you that the very fact that your boat has that plate tells me that she is an early 1973 or older model. A picture would further narrow down the year (I have the list of standard hull colors for most years). The manual for any year of the Widgeon may help, but there were changes in the rigging setup over the 1963-89, 1990-2004 production runs.
Interesting that your ID plate is missing several digits in the Hull#, for some reason, that is very common, Class#s are usually accurate on all models, but O'DAY Hull# is often shortened. Obviously, Class# is the important number as that indicates how many WIDGEONs had been built, where as the Hull# is refering to total O'DAY production of all models, if it was complete it could be compared to the Hull# of any other O'DAY at the time and if the year of that other boat were known, it helps narrow down the year of your boat.
I will echo the advice to call Rudy at D&R Marine for any O'DAY-specific parts! Rudy Nickerson was the Production Manager at O'DAY and now runs a little shop in Assonet. MA making ans selling replacement parts for our O'DAYs. He is on-line
www.drmarine.com with a page for the parts of each model. It is always best to follow-up any web order with a phone call (508) 644-3001 to clarify the order and check on shipping as Rudy often finds better ways of shipping if possible. He is also a good source for answrs to questions.