Chris - As you likely know, the 2101 had several incarnations, including as one of the locos pulling the Freedom train in 1976 (along with the 'more famous' SP4449). I looked quickly on Railpictures.com under both the 2101 moniker, with one link to the American Freedom train. Here's a link to one of the few pictures I could find there that shows a top (ish) view of 2101/AFT1: https://www.railpictures.net/photo/174399/
Apparently it is currently parked outside (unfortunately) at the B&O rail museum in Baltimore. Mitch Goldman, one of the best photographers on the railpics website, has a picture from a few years ago, along with a short historical writeup of the loco, here: https://www.railpictures.net/photo/568904/
You might consider (again, if you haven't already) call the museum and see if they have any photos in their archive and/or someone who could answer some of your questions about the whistle, the turbogenerators, etc. Maybe with a suitable donation to the museum you could sweet-talk someone there to take some pictures for you (assuming its still in one - if highly weathered - piece).
