I just purchased a bike that is identical to what I had as a child. The serial number by the rear axle is W149461. On the tank it says JC Higgins, and appears to be a JC Higgins Flightliner. However, even though “liner” is clear in the faded paint on the chain guard, it looks like it says Mainliner. I can’t find any reference to a Mainliner at all. I got my bike when I was eight or nine years old, which puts it at about 1963, and I found some information that the “W“ is code for 1963. Is there a Mainliner? What exactly do I have? Everything else appears to be original. Thank you for any information.