Ah, I knew I wasn't imagining it. (Sucks to get old, lol) It's there in the essay (I have the vinyl Promise set). While he says in the body that all of the tracks are from the Darkness sessions from 77/78, the * at the bottom of the page says:
* "Save My Love" written 1977, lyrics and recording 2010.
It's a new recording- I'm pretty sure Bruce said they had nothing, but he remembered the melody, and when they were going through the vault footage, they found the rehearsal tape (which is in the box), and he went, "Ah, that's it!"
And then he went and finished it. I for one am glad he did.
btw, where the hell is the UPS guy?