Just bought a 1929 Model A (Murray-bodied) 4-Door Sedan with title!
	
	
		I just bought a Model A Murray-bodied 4-door sedan -- with a title.  The car came without a frame and I'm trying to find the VIN.  I've been told that it's on the outside passenger side of the firewall.  The only tag I can see is a little rectangular tag mounted to the passenger side of the gas tank but anything written on it is hidden by a dark gray oxidation.  Is this the right location?  How do I clean this tag without destroying the information.
I have the title with VIN, but I just wanted to make sure I could see it clearly on the car in case anyone asked.