in the first and last pics, on the right rear corner, you can see the hull id number (HIN). When I zoomed in I could almost make it out, but the last 2 digits are the year. Of course the HIN should also be shown on the title and registration ... make sure the HINs on the papers match the boat, too
Agree with Mike, $2500 for a running boat that looks to have been cared for with a trailer is a low price. Assuming no major needs you could clean up the oxidation, detail the interior, add a new battery and probably come close to doubling your money on resale.