This is how it looks flatten and binarized at 127KB file size. Possible to read as this is the ultimate goal. But some text outline is missing, and more prior font outline improvement is desired so its not partially lost at binarization.
Ideally the font outline should be filled without defects, and its pixel color spectrum should be narrowed at cleanup close to black, so its not cut off to white later at binarization thus making small visible defects in the outline. The background might also contain close to black pixels as a result, and their removal may then require a different filter like despeckle. 
Talking to the site admin, since this site can’t show DJVU format when uploaded, there is a little sense in blocking other hosting sites links here for DJVU files, unless you enable showing them here. 