Fin Fin figures made by an unnamed "professional doll maker" (1995).
Makoto Tezuka describes the design process in Official World Guide.
Tezuka (translated): "We had the idea of making Fin Fin cute from the beginning of development. However, “cuteness” and “beauty” cannot be converted into numerical values, making CG difficult. So, I asked a professional doll maker to make several statues of Fin Fin based on my design drawings, and chose the cutest one."
Current whereabouts of the 3 Fin Fin reference models are unknown.