You might suggest a value for the repair and allow the seller to decide
wether to fix it or deduct the cost. It's a gamble.

Dodger snaps would likely be pop riveted or screwed into the top layer
of glass, as opposed to through bolted. Water might have gotton into
there, and will work it's magic as time goes by. Replacing rotton core
is a job you would want to avoid, but it is by no means an
insurmountable difficulty, especially if the dead sound is only in one
small area accessible from underneath, dressed up with headliner.

Beware of quick slap up repairs by the owner to facilitate a quick
sale.

Terry K