You make a compelling case To my eyes, the serial number on the bottom of the Schwinn Flyer looks similar to the one in the thread you posted. I got some pictures of the crank but didn’t see anything obvious. Hopefully somebody else will. The inside of the BB is red for what it’s worth so it looks like the frame was definitely repainted at some point.I'm still thinking that Schwinn is an early post war piece. I've been researching the evolution of Schwinn's electro-forging of their frames and that brings me out of the war time pieces and into the period when Schwinn started building retail balloon frames during 1945. Your serial number series H12345 was used in 1941. It's said and is fact that the prewar numbers were also used in 1946 along with the A and B series. The fact that nobody has seemed to take into account is that Schwinn was producing bikes for retail sales in 1945. These first post war models built in 1945 and some even say 44, were the first to have the chain stays EF'd to the BB shell and that process was a learning period for Schwinn. I've also noted there are two kickstand tube angles on these early post war pieces. Yours has the earliest version, but since that is a 24" frame that may be irrelevant. I doubt the crank has a casting date on it, but it's worth a shot taking a look and see if there is.