Odd. I tried both Sewer Shark and Jurassic Park, and got "Unknown Game" for both of them, even though they matched your hashes.
I would prefer to store them as CHD, personally, but I think I'm running into the issue with the CHD hashes mentioned earlier. None of the converted CHD files matched any of the hashes.
I used RomVault to match my Sega CD roms to the file hashes in your DAT, but RetroAchievements still doesn't recognize them. Do they have to be CHD to be recognized?
I noticed that the Series field is the one primary field that the Launchbox DB doesn't seem to fill out. Is there a faster way to fill out the Series field other than doing it all manually?