The label covering the factory markings is not important for operation. As long as you match the voltage, either 6 or 12, a new battery will have at least the same AH rating. A voltmeter on the battery will tell you the voltage.
The UL and warranty concerns matter only as far as they matter to whom they matter. On a warranty claim, Lithonia has the edge, as it's their nickel. Between us, I'd use a cheaper replacement if it was my nickel.
