This is pretty tragic for me because I made and open-sourced a bunch of "pretty good" DSL's, unfortunately they're still not cleaned up and completely undocumented. Also, all the usage examples of them are buried in some big abortive undocumented proprietary project with lots of newb-code (most of my mastery of Common Lisp was acquired by making this project), however I'm its sole author and own all the rights so I might consider open-sourcing it (perhaps under the GPL or something?). I had not considered this possibility until now mostly out of shame for the low overall quality of this code (with some peaks of high-quality I think, which might interest you).
I don't know under what kind of time constraints you're working, it's obvious that I won't have time to cleanup and document all of these in time, however perhaps if I do a bit of digging in these old projects (that I'm not even sure still build) I might be able to point you to the right places and maybe we can dig out a few examples of "pearls" in this mountain of shit? Who knows...
Anyway, here are some pointers.