I don't think so, Maskaev would've gotten KO'd around the time of those string of KO losses, Maskaev doesn't do well against wild brawlers he can't take out. The Corey Sanders fight was a perfect example of that. But I do agree that Maskaev had the skills to beat Peter, Maskaev was beating Peter before getitng KO'd.
Well, I don't think the 1999 Maskaev was prime... He was less wound up in the ring and a better ring tactition around 2007ish. In the Peter loss he pretty much didn't train and was in bed rest leading up to the fight, he really shoudln't have fought. But if he didn't he woud have been stripped of the belt, yet he still gave Peter a decent fight. Take away the bad back, shitty cardo, the extra weight, wasting muscle and rusty skillset from not properly sparring, and I'd think you have a great argument that Maskaev would have toasted Peter in the ring.