Sears sold the Flightliners under the JC Higgins brand name up until 1964 when they dropped the JC Higgins name and started marketing the bike as a Sears brand. Same basic frame but painted or chromed, springer fork or regular fork, racks, and tanks.The tanks differed by years as did the chain guards. Basically Daddy was paying more so Sonny could have more bling to show off.
The same basic frame was built by Murray of Ohio on bikes sold by other department stores but had different designs for tanks, lights, and decals. Each store marketed bikes under different brand names. There are two threads on the CABE well worth reading. "The Murray Serial Number Project" and a thread on Flightliners and Spaceliners. The Murray Serial Number project is buried in the general section. Easiest way to find it is to Google the title. The Spaceliner thread is pinned to the top of the Middleweight section.