I saw this on another site, downloaded it and think it's something to make available to folks on this site. Jeffrey Funderburk has made a 57 minute video on tuba/euph-- particularly rotary valve-- maintenance and minor repairs. The picture part leaves something to be desired, but the commentary is first rate and the information is very good and useful. The download might be a challenge for those of you on dial-up, but the video is quite worth it.
http://www.uni.edu/drfun/FunderburkIndex.html 