late 80's, made by Aerofast Bicycles. they also did the columbia re-pops. they're really well built bikes, made in USA, and the frames and forks are guaranteed for life. they used mostly american made Wald parts, and Shimano hubs. no cheap chinese stuff.
they still make the same bike, more or less, and they ain't cheap.
edit: i think the serial number on the headtube should tell you the year, also. should have an 88 or 89, or whatever in it.
it's pretty easy to tell the difference between a re-pop and an original. for one thing, the bike doesn't look anything like any western flyer ever made. the frame's different, forks are different, everything's different.
but if you're not that knowledgeable on older western flyers, there's plenty of give-aways that'll tell you it's not from the 50's.
if it's all stock, the re-pop will have reflectors on the pedals, stainless phillips screws on the tank and chainguard, decals on the tank, chaingaurd and frame (originals woulda been painted, and have a metal headbadge.)
also, it's gonna have a shimano coaster brake, instead of a bendix or some other american made one.
not to mention, it's pretty rare to find a 50's western flyer in pristine condition, no rust, not even any paint fade. that's the biggest give-away right there.
but like i said, they're great bikes. they're actually much better built that an old western flyer. they have heavy duty 12g. spokes, kmc chains, and great chrome.