Just recently came across this nice performance video of Richard O'Brien singing The Time Warp live (with his acoustic guitar as usual) on February 19th, 2000 at Shepherds Bush Empire in London:http://www.rockymusic.org/showvideo/cde9358392f13c70f66fbaf231a4ee98.php
He's apparently performing with the SAS Band, though they're really only heard as unseen backup singers. The SAS Band ("Spike's All Stars") being some sort of a constantly fluctuating band around Philip 'Spike' Edney that performs periodically with various guest vocalists. An MP3 of this audio track is also available from Amazon MP3 Downloads:http://www.amazon.com/Time-Warp/dp/B000QLMRNG/ref=dm_ap_trk1
The CD that's taken from ("The Show") appears to still be in print from CDBaby actually, though at the rather extortionate price of $30 (I've never seen anything priced like this at CDBaby before):http://cdbaby.com/cd/sasband2
Richard O'Brien only sings on the one track.