Go inside of the boat and found a cabinet locker or a
bilge area below the waterline, you know this spots where the
builder forget to aply a layer of
gelcoat or
paint, cores are easy to spot inside , normally you see the blocks of balsa trough the inner layer of glass, get a flashlight to see it better, i hope that model dont sport a horrendous pan liner and you can reach a spot where the
core its visible, and nothing wrong with the core if the boat get a well
maintenance over the years, truhulls , moisture,
blisters etc... or ask to the owner,
broker to remove a truhull , not big deal..... good luck.