Yeah, get some evergreen styrene strip the same depth you'll use. i made mine a teeny bit longer to make it look more like the Derelict Version. make ONE fin that you like from the strip, and then duplicate about 35 times. pick out the 32 best fins and glue in place. glue them while the fusion core is upside down so any glue won't mess up the bottom.
I would use Evergreen styrene strip and use my Northwest Shortline 'Chopper'.
I would make a small jig out of styrene to hold the strip styrene at the correct angle and just chop identical pieces off ..