I just became the happy owner of an MK2 26 from 1971-
It has the 3'2" shaol keel, but it also has a retractable centerboard. Centerboard winch in directly behind the mast- the cable runs through a pole in the cabin a little aft of the bulkhead line.
Does any one out there know anything about the Mk2's being built with centerboard's? I can not find any information about this--- was it an aftermarket add on?