Thank you for your response and suggestions. I actually just bought this board on an auction site. It was described as 'as new condition' with the exception of a small ding that was clearly photographed and described. Once I received the board I could see some damage around the fin box and the stress fractures within the fin box, which were not described in the correspondence with the previous owner.
As suggested, I checked the fin bolt alignment with the bolt holes and everything looks to be aligned correctly, the nuts in the fin are aligned dead center with a several mm gap between where the outer surface of the bolt would be and the surface of the bolt hole. I guess that the previous owner just applied too much force.....
In your experience are the stress fractures that are pictured in the previously attached images likely to cause any problems... is it ok to use the board as is or should this damage be fixed before I use the board....