BREAKING NEWS!!! I am not losing my mind! The F/A Drifters in fact have a STEEL BELLY PAN... took a second look. The foot stirrups are also different on the F/A's. Looks like the tunnel is the same. So, just to clarify my own question... the Fans and Free Air are a bit different. I suspect the steel pans were used on the F/A's to cut costs. You learn sumpin' every day.