quadfish fin (re)placement...

received a project from a friend - seems the fins were in when being transported & the front fins got jammed into the board so that they had to be removed. 

was able to remove them and keep cut-outs clean.  i have the cant marked out but am unsure of the angle…i have a quad myself but is built by diff. shaper & 

for diff. waves (my angle finder says they are ~ 12 deg. off 90 (102 deg.)).  what are some other common angle(s) for the front fin of quad fish type boards…

this one i’m wanting to fix is a jeff clark flying fish.  thanks for any input ahead of time.

what are the dimensions of the board?