Classic/Antique Car Repair: 1929 Model A, Battery, Polarity

Question
What voltage is this automobile ? ( I forgot 6 or 12 ? )

When I look down at Battery I cannot tell what side is Positive or Negative ( one side has an exposed ribbon cable vs the new car insulated cable )

Help !

JR

Answer
All of Uncle henry's cars of this vintage were 6 volt with POS to ground and NEG to power us the car. When looking at the top of the battery the POS terminal is always slightly larger in diameter than the NEG terminal. The braided strap is the ground and in this case should be connected to the POS side of the battery.
Brad