We have success! I don't even think the fonts/character sets were the problem (the asset filename references were garbled in what I got back, but I just relinked them). The key is that he needed to provide more files than just the .ncor file, which is the only file he sent the first time. This time he sent the whole structure, and although the folder structure and most of the files were unchanged, there were a few files besides the .ncor file that were generated or changed by Encore 2.0. So if you try to do this, and are using a different computer or another person to help with the intermediate step, here are the files you need to update/add to the original structure after 2.0 does its work:
* MyProject.ncor
* MyProject/*.* (two files)
* MyProject/Sources/Menus/*.psd

Perhaps this will help someone.