Pure F/G or Cored Hull - Locate Information?

[Delta Mitch]

I was in the market for a used boat, and wanted to ask if anyone knew of a source of information that would indentify what boat builders used coring in their hulls (below the waterline), and which ones were pure fiberglass?

I know this is a long shot, and many companies change their construction techniques over time, I just thought I'd throw this (dumb) question out there...

TIA,