Don't know about Lindbergh (do they use optical media for storage?), but QA definitely has a HDD image inside. Of course, you could extract the files and burn them to a CD, but that's probably not what you wanted...
NB: CHD stands for "compressed hunks of data" and is what MAME uses for, well, basically anything that's not "a ROM", i.e. stored on a chip, be it a CD, HDD, DVD, what-have-you. No way to tell what's actually inside just by that extension. Think of it as a .zip.