Niece piece of misleading BMW advertisement here, hopefully it's not for free...
The supercharged RS 255 won three worldchampionships in a period when there were no worldchampionships ?? Georg Meier won the European championship in '38 on this bike and a couple of post war titles in Germany as long as supercharged bikes (till '51) were eligible here. And certainly more than one RS 255 has survived, only the old dispute who owns the 'real' Senior TT winning bike of '39 seems to ge going on. By the way, BMW had a very ambivalent approach when the BMW RS 54 Rennsport engine dominated the sidecar worldchampionship in the sixties and early seventies with hardly any support for the ones who ran the show.