noticed the black paint has come off all the way around the inside of the holes in the deck the fin bolts go into, is this normal? The paint missing from the bottom of the hole is where the bolt head hits so espect it there.

Depends....it that a crack where the box "tubes" meet the deck? If so, could be a leak point eventually. Somebrandswerevery prone to that with some box types.

If it is just paint falling off its unsurprising as it is just a touchup on plastic (ie poor adhesion on plastic anyway) and to be expected eventually I guess.

Looks suspiciously like the sandwich box join to me. If that's the case as Mark says it's caused by movement between box and sandwich, not a good scenario!
But it could just be a proud point and you've worn the paint off by screwing the fin in.
I think you need to check more closely to determine which alternative

Looks sus to me. Looks like the box is rocking side to side .Soapy water in the sun.?

It's all good man.

I hate these half height tube boxes they put on production boards. Completely undermine the strength of the fin installation for a few grams of weight.

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Stuthepirate said..
It's all good man.

I might have to get the black pen out and do that!

Sometimes, those cracks can be unpredictable. (Seriously, though, I'd find this a bit unsettling. These are the same type of boxes that foils rip out, too.)