The handiest option would be if you can get your hands on the complete installation, especially the Products/ folder. If you have that, you can probably start it up just fine with python 2.1. Find the etc/zope.conf file, switch on FTP access if not yet enabled and copy everything out of there onto your harddisk. That s the quickest way to get everything out in a format that you can work with.
Alternative if you don t have access to the complete installation: try to set up an old debian somewhere that contains zope-cmfplone 1.0.1. Copy the Data.fs to the correct location (I d guess in /var/lib/zope or so on such an old debian) and start the server. And do the FTP trick again.
Alternative 2: if the exported zexp xml contains all the content, you can take a quick look whether you can extract whatever you need from that.
Alternative 3: the Data.fs is readable with a standalone ZODB package. The Data.fs contains python objects that are readable from within python. Get yourself an older zope or standalone zodb package and open the Data.fs. As you don t have the original software, apparently, the python classes used to make the objects aren t available so the objects will be pretty much broken. With dir() and dictionary access you can try to rescue as much as possible.
Alternative 4: was it a public site? What does http://archive.org have in store for you?
