1928 Oregon Trail Commemorative Silver Half Dollar. MS66 CAC “WitterBrick” silver edition handpicked and signed by Seth Chandler, co-founder of CAC. Please look closely at the pictures and grade the coin for yourself as this is the actual coin you will receive. We do not offer grades on raw coins, and we do not guarantee grades on raw coins. If you are biddin. Member in good standing with the. , Numismatic Guaranty Corporation (NGC) and the American Numismatic Society (ANS).