Isn't your university library plugged into a decent interlibrary loan system? The Pacific Northwest interlibrary loan system that my college is a part of has never failed to turn up any book--including some pretty minor texts. And actually, it seems that my university library has a 5 volume set of what it calls "Lancelot (Prose Cycle)," which seems to be the same thing. That is actually pretty surprising because our university library isn't terribly large.

I guess this is a long way of saying if you're looking for some specific piece of information or something, let me know and I may be able to look it up for you next time I'm up at campus.