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?