You can always go to Frank's site
www.mahoganyrush.com and get his later releases that he remastered himself, and at least he will get his 'dues ' from these purchases.
I know that it doesn't cover some of his earlier releases but that is down to Sony (CBS) getting him to sign his rights away when he was young and naive.
Also BGO Records did remaster Mahogany Rush IV / World Anthem, Live/ Tales of the Unexpected / What's Next, and The Power of Rock and Roll / Juggernaut, although I tried to arrange for Frank to actually master these, they refused to let him, and Frank told me that this would happen, and was really done without his approval.
But like Frank said, they paid Sony for the right to do this, even though they won't let Frank do so.
They told Frank that the original master tapes had been wiped, and many of his true fans have scrutinized these so called remasters stating that they are either vinyl to CD, or even CD's with the levels boosted up.
Frank has said that they are not remastered at all, as without the master tapes there is nothing to remaster, basically these so called remasters are just digitally enhanced copies, as true master tapes are done on 8 track and upward machines so that each instrument has it own track, once they are mixed down to 2 tracks you lose the ability to 'remaster'.
To most of us though you may never hear the difference, it's like the argument about, Vinyl, CD's, mp3's and FLAK.
Personally I believe that vinyl still sounds the best, and each 'progression' of the format tends to sound tinnier as they go along.