Wow, never heard of Jimmy Nail, so I'm guessing he didn't do much in the USA. Steve Earle and Chris Ledoux are/were country singers I think, and RM doesn't do Country. OR Western.
(tribute to one of the best movies of all time, The Blues Brothers).
There was lots and lots of fantastic music from the early 70s, although it went downhill by the mid-70s. And I usually know stuff from that time pretty well (although I often forget what I had for lunch the previous day), but it has to have been somewhat known in the US. I know very little Aussie stuff.
I knew a grand total of 3 from this set, and two are already gone (Elton John and Styx). The Janis Ian song tickled my memory, great snag Dionysus, pretty impressive. The only one I can add is
#6 -- Black-Eyed Boys, by Paper Lace again.
Good luck on others.
RM