This seems to work for me, however it's PAINFULLY slow. I *think* I fixed the speed issues. Now it should take just a few minutes, although I haven't really tried to flash the resulting files. Please report if it works here or send me a PM if you have any issues. Granted I may not be held responsible for any damage derived from my work.
You may either download the original zip file from the OP and replace "runme.sh" with the new version I provide below (just rename runme.txt to runme.sh), or just download the whole thing which includes the new file, whatever suits you