Thanks to all for all the comments. Ill Try and answer some of your questions.
I make the side fins seperate and join them to the fish. Depending on the size of the fish i do the same with the top and bottom fins.
Scally, i have seen fiberglass fish made in the style you mentioned and i have been thinking of having a go at that style.
Lastly, they are not copies of the fish i catch, i would have to downsize the tools for that.