I am buying a Contessa 26 with a purported HIN of SNZJT033080885.  I don't think there is a hull identification number plate on the boat.  Looks like a boat built in August 1985, but the sail number is out of sync with other boats (according to the contessa registry, that sail number is from 1983. Any insight?  Is it an '83 or an '85 boat, and what does one do when there is no plate?

Much thanks!