I found an old installation CD for Office 2007, and surprisingly it loaded and worked!

I've created a spreadsheet that compares the files in the STYLES directory with the tab delimited text file I exported from the style picker.

Cells are highlited yellow when the filename is in the folder, but it isn't being shown in the style picker.

Hopefully if a programmer is armed with the exact list of styles that aren't being captured it will provide enough evidence to figure out why.

LINK TO SPREADSHEET

The file opens on tab one, but it's the third tab which provides the side by side comparison and display of missing files