The 1849 Moffat & Co. gold coins are considered collectible pieces from the California Gold Rush era. These coins, minted by the private Moffat & Co. in San Francisco, were primarily used in commerce and were vital for local economies during the gold rush. The "G 9 43" designation likely refers to specific grading information concerning the coin's condition or type. Collectors often seek these coins for their historical significance, unique designs, and the limited number of specimens available.