more or less, I refer to them as cousin's rather than true sister ships.
Mine (Comfort Zone) was to the original design but stretched and there is a second one off the same moulds that to my knowledge has never been launched, I believe still in a shed in Avondale. Interestingly quite a few of her drawings including the lines plan were drawn by Roger Hill in his role as Farr's chief draftsman.
Alan Smith/Smith's boat yard Whangarei decided to build these for export to USA and had the Farr office tweak the design (removed the clipper bow, different interior, longer cockpit with LOA 13.