Great looking bike! Here's a little info I dug up:
Murray produced the X-53 Super for Western Auto from 1953 to 1958... The skip-tooth chain and sprocket were used on the '53 - '55 bicycles, and the '56 - '58s had the 1/2 inch pitch chain. The fenders were painted for the first year or two, '55 and up had chrome fenders. The early ones wore a black and red paint scheme (Boys version) or two-tone blue for the Girls. Only a Boys model was offered after 1955, these and the '56 models wore a red, or red and gold paint job. The final run '57 -'58 were black and gold.