There is a modified Mk2 for sale in Grafton:
https://www.gumtree.com.au/s-ad/wooli/s ... 1141331231
The aft end of the keel appears to have been cut back, a new skeg created, and a transom mounted rudder added. No doubt it is more manouverable, and maybe points higher. Extra room in the cockpit too. Anyone seen this boat before?