I am sure there are issues, and the code isn't the cleanest!
But it was fun.
On a side note, I also did a diff viewer (it lets you merge or delete a diff block on a block by block resolution).
http://www.ragedcom.com/punt/diffs.rar (once again, need qt.rar). set the diffs.xml to your direcotry where the mul files are.
Gives you a block display of your map, with color in ones that are patched via diffs (two views, one for map and one for statics).
Then you just double click on a patched block to get an image of teh before and after, as well as a list (recall, some are blank).
You can then either merge that block, delete that block, or "keep" it (decide to change a merge or deleted block back to its oringal patch state). merge merges that block into the mul. Just do a save, and it writes it to the muls.
Not really part of the suite, but something I needed for one instance. The image for terrain isn't stretched, I just offset the tiles by their altitude (go to the list for a detailed view of the information).