In some cases, such as the 'total editing time', you can edit the value stored in the .docx file.

To edit the 'total editing time':
1. change the .docx file's extension to .zip
2. open the zip archive and look for a file named app.xml
3. open the file named app.xml and look for a string like:
<TotalTime>600</TotalTime>
where the 600 is the stored total editing time value, in minutes.
4. change the stored total editing time value to whatever corresponding 'old' value your .doc file had.
5. close and save the zip file
6. change the .zip file's extension to .docx
Done.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]