Hey that was my plan to do as next step! However, thanks for doing a part of it. You've done good work.
I plan doing some data analysis, since I already downloaded all the levels from the archive a few months ago, and stitched together some tools to export and analyse them. However a lot of manual work will be required, so having some of the these tilesets linked to their authors in filenames will help me a lot (I will be able to match them with the analysed content).
I wanted to announce this idea later, when I would be sure, but after reading your post I realized, I could make it much easier for you right now, when you want to continue extracting the tilesets. If you want, I can send you all the exported tilesets at once, however I need some time to polish some things in the scripts to make the export more useful.