Rocketry blogger, the 'Rocketaholic', just dug into his archives and posted photos from a Reaction Research Society class and documentation of his Systeme Solaire SS67B-2 liquid fuel rocket. These are interesting posts and are worth your time. If you have a big computer screen you might even be able to read the text in the photos without additional steps.
When I joined Tripoli, their magazine (High Power Rocketry) featured ads for the SS67B-2, liquid design resources and even plans for liquid rockets. This was along with announcements for solid motor classes from RRS, Thunder Flame, and possibly other sources. Liquid rockets, except for the RATTworks Tribrid which adds alcohol to the standard NOX hybrid, have never been allowed at Tripoli events. If tribrids can be certified, I wonder if there is a crack in the door for other liquids? Yeah, I know, they are complicated, expensive and dangerous. But if you let someone else do the development, these factors might be mitigated. I'm not sure MDRA would allow them due to potential fire damage to crops. But, the folks in the west have access to barren launch ranges. Just thinking out loud...they aren't for me in any event.
The SS67B-2 used 50% hydrogen peroxide as an oxidizer and super unleaded gasoline. It was very expensive although the cost per flight could be negligible. It was also complicated and likely dangerous too. Rocketaholic's post is the only detailed, first hand report that I've seen. The SS67B-2 is also commonly thought to be a poor performer. His flight report mostly reflects on the fact that it is complicated. (Excuse the fuzzy photo.)
Update: I poked around on Google and found that Systeme Solaire was offering a new version, SS67B-3, as recently as May, 2009. And, how the heck did High Power Rocketry get ahead of me in the Google pecking order?