Eleven lithographs signed by the Spanish surrealist Salvador Dali sparked an auction battle on Monday after being stored and forgotten in a London garage for about 50 years. The prints, which were found as the seller cleaned up his lock-up in the upmarket Mayfair area, had been bought in the 1970s at an art gallery closing down sale for GBP500. Chris Kirkham, associate director of auction house Hansons Richmond, said each lot exceeded its guide price of between GBP500 to GBP700 ($670 to $935). The most sought-after — an abstract colour lithograph of nude figures, a limited edition print signe…