I am away on my summer cruise, and struggling with just a recalcitrant mobile device, so I hope this makes sense !!!
According to my records (unofficial, but derived from data published on the old Bravenet forum around 15 years ago, with limited updates since then), hull numbers 6001- 7000 were issued 1963-66.
Fuller information would be obtained by asking the Association office for a copy of our digital records for the boat (free to members, if I understand the situation correctly).
Hope this helps.
Oliver