When I open a PAF file most of it is not text, so I can't believe that you are going to be lucky fixing it. There's not enough of a market to encourage someone to develop an application with enough knowledge of PAF files to be able to attempt a repair. Thus the reason back-ups of data files are so important. Have multiple back up's on different removable disks, kept in different places (preferably with other family members).

The only suggestion I have, and it is painfully inadequate, is that you can find apps on the net that will strip out text from a "binary" file for you. Not personally used one for years but I used to have one. Then at least you have something to copy & paste from when you start a new replacement tree.