Giving a shout out to barracuda surfboards. After a couple of average jobs from the other local repair dudes, I took my boards to 'cuda. Have had 8 repairs done now on surfboards SUP and kites boards. Mostly fin boxes and channels and rails- too finicky for me to try. solid job. They just refinished my favourite kitesurfing board- the 5'11 OR custom surf poly and I was impressed with the results

They may know their surfboard stuff but beware getting a windsurfer box redone. They replaced the fin box on my fave board and totally botched it. They didn't sink the box in deep enough and then ground off 1/3 of the box because it was sticking out. The result was that the fin would not even fit in all the way, so then they destroyed that box to remove it and started all over again. Total time without use of the board = 2 1/2 months!! And then cracks developed around the new box after 6 or 7 uses.
They just don't seem to understand how much side force is on a windsurfer fin and therefore don't reinforce it enough.