Frustrating! I raced through about 95% of the gridfill in record time (for me) but I still have a handful that I can't solve (1, 23, 29, 17, and 27). I have the quotation, I've highlighted the author, I know where most of the symbols are and what to do with them, and where to place the final 2 lines.
I've probably spent three times as long trying to resolve the above as I did actually reaching that point. But tempus fugit so I'll put it on the DNF pile. Nice one though, Vismut.