Help ID serial # dating on Flightliner

[Da e]

Picked up a frame on Craigslist. It looks to be a JC Higgins Flightliner, or Sears. Has the typical pointed drop outs, dual top tubes, tank/ headlights is missing, serial is on left drop out. Has a Kome 1 super rear hub.
502 45201. 492872
There is two brads where a possible head badge once was on the head tube, they may be how the tank/ headlights mounted. IDK..
Hope you guys can give an idea of the age of this frame. Sorry no pics yet.

 

[Rustinkerer]

4520, or 45201, is part of the Sears catalog code. Sometimes, you can match the # with a specific year in the catalog. I took a quick look through my info, but didn't see that #. But, the Flightliner frame style dates from 58 through the late 60s. -Adam