First off, are you working on the same platform as the one on which the doc was created? T1 fonts are either Mac or PC format, and they don't work cross-platform in the Document Fonts folder. You can put PC T1 fonts into the InDesign Fonts folder on the Mac and they should work inside ID, but Mac format fonts of any type are completely useless on PC.
If these are Mac T1 fonts and you are working on Mac, they might work from the the Document Fonts folder, but my possibly faulty memeory is that T1 fonts in general don't work without installing them someplace on either Mac or PC (I'm fairly certain they don't work on PC from the DF folder).
Yes you are probably right, I'm on PC and the file was created on a Mac. Thanks for your reply!
No chance those fonts will work for you. If you check the file size I bet it shows 0 bytes.