Bull on PSA. I would go to
http://olympinclub.com/ and at the top navigation bar there is an option 'Resources'. The drop down has an option 'Ask the Experts'. One will say Olympic medals: Jim Greensfelder. If you click on his name you can send him an email directly. To make it more efficient I would have scans of the medal and if possible diameter in mm's and weight in grams. The fake medals can get the design and dimensions correct, but never the weight. Disclosure: I am a long time member of Olympin and one of the experts on two subjects.