How to open these ZiP and cpgz files?

I have some of mu old Word files that are now listed as ZIP archive files (I don't recall compressing them, but there they are). When I try to use the default Archive Utility app they become cpgz files. When I try to open them with The Unarchiver I get a folder with three subfolders: _rels, docProps, and word. Each of these contain other files but none is a decompressed file. When I try to use the unzip command in the Terminal (I'm not very familiar with Unix) I get a bunch of "replace " questions. I hit yes to all but nothing seemed to happen. And when I tried to use The Unarchiver on the cpgz file that was created with Archive Utility I get a message "There was a problems extracting the contents of "filename": The archive file is incomplete".

I also notice that when check "Get Info" on these files none has a .zip extension and the "Hide extension" option is greyed out. I tried adding the .zip extension by just typing it in the Get Info box but that didn't help.

Are these files corrupted? Is there any other way to try to decompress and open them?