Tim: I'm fairly sure that he would have gotten royalties when the 110 purchased the sheet music. Purchasing the music typically comes with a license allowing the band to play the music, or at least thats the way it worked for my high school marching band. If that is the case (I don't know if the 110 has purchased, of indeed ever played, the song) then disallowing the song in the future would have no impact on said rapist.
Two different things. The physical publishing rights give him royalties, but so do the performance rights. PRS (through its partnership with either ASCAP or BMI, which I believe it's BMI in this instance) uses various (and secretive, also controversial) techniques to measure how many times and in which places music gets performed. Believe it or not, there are agents around the country who go to places where music is performed or played and measure it. This is how local bars get shut down for allowing cover bands to play when the bar hasn't paid its annual dues to the publishing companies. The agents also regularly attend sporting venues to measure what and how songs are played.
It all eventually goes into this huge database by which they determine what portion of the lump sum gathering of annual payments goes to which songwriters. So songs that get performed often (such as R&Rpt2) earn a larger lump.
It's a miniscule percentage, but it's also a lump sum of several billion dollars. In the end Gary Glitter makes, I believe a publishing company agent estimated, somewhere north of six figures purely on performance of the song.