The fact that this boat has that metal plate with a HULL# and CLASS# on it tells you that she was built prior to the November 1, 1972 start of the USCG-Required 12-Digt Hull ID Numbers. So, you do not actually have an HIN (although States now issue HINs for older boats when you apply for a Title or Registration). HULL# 3227 CLASS# 2538 seems a little "off" since I think that HULL# should have one more digit (seems common that either the plates didn't get the whole Hull# stamped or it is just hard to make out) Hull# refers to how many total boats O'DAY had built (so yours appears to be the 3227th O'DAY built?) CLASS# refers to how many of that model had been built and would be the number displayed on your sail. So, you have the 2538th JAVELIN built. I'm suspicious of that HULL# because judging by the CLASS#, your boat appears to be a 1971 or early 1972 model (1972 O'DAY brochure boasts that "over 2145 Javelins have been built" and that would have, in theory, been based on total up to some time late in 1971) and my old 1969 WIDGEON was HULL# 22698 and would have been built about 3 years +/- before your Javelin. I think the HULL# on your boat must actually be between 32270 and 32279?? But, really the CLASS# is almost more important since, as I say.... that is the number used to ID your boat within the Javelin class and may be the best reference for the Javelin Class Association to determine the year.
I assume that your boat is the "newer style" JAVELIN, with the molded, self-bailing cockpit and enclosed compartment under the forward deck? Those were introduced in 1971, the earlier boats were all open bow to stern with a deck over the bow that was not enclosed and the seats were molded separate from the deck.
Interestingly, that 1972 Brochure lists Mrs. Daniel J. Reiber as the contact for the Class, and on YAHOO there is a Javelin Forum where the Class "Expert" is Dan Reiber! So, let me post a question there about this matter and maybe we can get an answer! Contacting the Manufacturer won't work, O'DAY ceased operations in 1989. Rudy Nickerson, who worked at O'DAY as their Parts Dept. Manager from 1973 to 1989 now runs a great shop supplying parts for our O'DAYs, D&R MARINE (
www.drmarine.com) and he is quite an expert on O'DAYs, but this boat was built prior to his time at O'DAY and unfortunately, most of the old records of O'DAY are long since lost. It still might be worth calling him, (508) 644-3001.