You're welcome. However:
I didn't build the bootloader, I just developed the pinout I wanted.
maniacbug did the software. I had something mangled together for IDE -0023, but the change for 1.0 was more than I was able to figure out.
I think you can copy the 1284P section in avrdude.conf, call it mega1284.
Then do the same in boards.txt, make a new section with new name and call out mega1284 vs mega1284p
Should let you have 2 versions and not have to switch back & forth.
Worth a shot anyway!