I shot the 819 in 1988 and did a video on it. it did have a squeeling whistle, that sounded like a sick dog, for lack of a better description. However, by the time it ran to the NRHS convention in 1990(St. Louis), it was either fixed or a different one was used, which sounded much better. That was its finished moment,in 1990. My fondest memory is shooting video of it crossing the Mississippi River while a barge went under it. She did some 60 mph plus running on that trip.
The whistle was not an air whistle by the way.
Greg Scholl