I remember those rusting out when the bikes were still current.. Let's see some images of the cancer. A talented sheet metal guy can fabricate some patches for the entire underside and weld them on with fairly decent looking results.
Too much is just barely enough.....
2007 Tiger 1050
2005 Royal Star Tour DeLuxe
1973 Yamaha TX750 1984 Yamaha RZ350
1974 Norton 850 Commando Roadster