The night before the World’s Greatest Rock & Roll Band stopped its massive Bridges to Babylon tour in front of 50,000 hooting fans at New Jersey’s Giants Stadium last October, bassist Bill Wyman made his first public appearance since retiring from the Rolling Stones in 1993. At London’s Forum theater, Wyman, now 61, was playing — and singing — with his new band, the Rhythm Kings (which includes Peter Frampton, 47, and Georgie Fame, 54) at a stop on the group’s first-ever tour. In addition to his music, Wyman oversees his Sticky Fingers restaurant chain, is writing a history of English manor houses, and is at work on a book of photos he took of artist Marc Chagall. Still, the soft-spoken man who caused a scandal in 1983 by professing his love for 13-year-old groupie Mandy Smith (when Smith turned 19, in 1989, the pair married — and divorced less than two years later) said his major project these days is just on the horizon: Fashion designer Suzanne Accosta, 34, his third wife and mother of their two daughters, is expecting their third child (Wyman has a son, Steven, 30, from a previous marriage) at midyear. That’s satisfaction.