My research tells me the only one of its class that survived was 3463 which has been on static display since 1956. Is that when the rest of the class met its demise? Did the Blue Goose keep its streamlining and blue paint job throughout its service life? It seems odd to me that if they were only going to keep one as a museum piece, they wouldn't have kept the Blue Goose. My Google search has turned up more information on models of the Blue Goose than the prototype.
I believe some of the skirting was removed from the 3460 "Blue Goose" towards the end of its service life. So far I cannot seem to find a photo that supports that. But I did find a photo or two of the engine looking rather ratty after its glory years. The Milwaukee Road streamlined Class A 4-4-2s also started to look very battered towards the end, and none of them were preserved, either.
Repeatedly removing and then replacing all that streamlining for regular scheduled maintenance took its toll and my hunch is that both the As and the Blue Goose just did not look nice enough in the 1950s for the railroad(s) to consider preservation.
Dave Nelson