the last 8 digits 31150314 were pre-stamped (from the back) on the VIN tags, the first 2 digits were added (from the front) when the car line and model were finalized.

3 = 1963
1 = Lynch Rd. Detroit, MI assembly plant
150314 = VIN sequence number (started at 100001)

50,314th assigned VIN at Lynch Rd. for 1963