"If Iggy's observations are accurate, I reckon that (using a process of elimination) the following five songs must be the ones he's referring to: Some Weird Sin, Tonight, Success, Neighbourhood Threat and Fall In Love With Me. Not bad for five hours work!"
Iggy suggests (in Word) that Bowie re-wrote some songs for LFL, see above. I've always thought "Neighbourhood Threat" was a re-write of Fleetwood Mac's "Rhiannon", which might be accurate considering the above revelations.
I'm not sure they got it right, though, as Tonight and Some Weird Sin were performed on The Idiot tour, i.e. they were not written during the LFL sessions. However, NT, Success, and FILWM might have been re-writes.
Assuming there's truth to Iggy's statement - which original songs are the likely blueprints for the LFL tunes? Iggy said that he did not want to reveal the original sources, but fans out there might be able help out!