Wood boats are all Mk1 type and there was a Mk1 Grp boat made in the first use of Grp.
Mk2 in only Grp is more resent and much more available. Also Grp parts for that type are available for replacment and upgrading.
Mk2 Grp is a stronger made boat than the early Mk1.Used for all kinds of Wayfarer sailing and at all sorts of prices.
Good Luck with your search.
C P 🙂