This is an Original complete kit I found and the fins were cut out. So I have finished it all except the paint detail. One thing I always do is 'skin' the fins with yellow file cabinet paper for strength/finish. I used Elmer's Carpenter glue brushed over the fins and lay a cut out of the fins over top. This is a Great thing to do for obvious reasons. They always come out smooth and strong, and last forever. Eliminates sanding sealer and all that work. Hope you like it. Incl. is my other one I built in the early 80s which is, also, an Original kit.