He does a lot with legacy acts but I think that performance has more to do with his connection to Ozzy.  Guy seems to insist on playing on stuff, though. I vaguely recall a Duff interview when Ordinary Man was coming out talking about Watt playing some guitars on the album and it sounded a lot like how he would talk about Frank, so i wonder if that would be a sticking point (outside of Axl’s obvious preference for producer).