The whistle on 1218 was the same pretty much its entire time(1987-1991). It was an authentic N&W hooter that was common on the freight engines.
John Craft and I chased the breakin run from Birmingham to Wilton in April 1987, and it sounded like a screamin banche. Frank Collins the engineer, told me that some of them actually sounded like that in service. Well they made a few adjustments and it didn't squeel much after that. It was a pretty haunting whistle though, kind of a cross between 489 and 463 on the C&TS.
We all miss 1218 and Frank.
Greg
Don't have any pictures in my Gallery of N&W so the tape jacket below will have to suffice.
Maybe Craft can spare a couple of 1218 or 611 as well at this point.