Maybe I'm delusional, but it seems like any of those units could come back, anytime. Anyone see old shots of Billerica from the 80s when claws were devouring engines and turning them into scrap? These all look intact, so who knows?
Some of those 1st gen units look "stored" as opposed to "dead" to me.
But just by looking (especially from the air), we're guessing.
Another thought-- none of the engines at Waterville are whitelined.
In the SD-26 scrapping days, the whitelines were lined up like cordwood.