When the 4449 first came thru El Paso as the American Freedom Train and then again in the early 80's headed to the worlds fair, a group of us that was maintaining the SP 2-8-0 #3420 we worked on the train from El Paso to San Antonio, it was a blast to say the least. We were chatting with Doyle McCormick the 4449 Guru and he told us that the whistle on the daylight at that time was not the original whistle but one from a steam boat from the Mississippi River boats. Not sure but they probably found a whistle that was from a steam engine somewhere in California and traded it out. Then again, it might still have that old steam boat whistle. Either way, it sounds fantastic. If there are no other GS class locomotives running that are totally intact, then how do we know what it really sounds like? If Doyle hadn't said that it was a steamboat whistle, we would have never guessed it. Sounds great to me and from all the videos I've seen of it, it sounds like it still has the SB whistle. It was also my understanding from talking with ex-SP shop guys, no two whistles were ever the same, there was always some tonal variation.