Vintage 26" Boys Monark Silver King Rocket Bike

My $17 flea market find today, bargained down from the $20 asking price. A little oiling here and there and some air in the original Goodyear tires and I was up and riding around all afternoon. Serial number was so lightly stamped that it can't be made out. Must be a model year nearing the end of the balloon tire era. Late 50s early 60s maybe.