Extracting a multi-part tar made with 7-Zip in Windows

I had a large file (66MB) in Windows, which I wanted to upload in ~3.5MB parts via FTP to my web server. I then planned on telnetting to the server and recreating the original file on the server.

I used 7-Zip to create the Tar file(s) in Windows, and I used the "Split to volumes" option. This gave files:

filename.tar.001,
filename.tar.002,
filename.tar.003, etc...

I uploaded the 21 of these to the server via FTP, and now I'm looking for a way to extract the original file?

I've telnetted in, and tried a bit of tar and copy, but no luck so far. Is there anyway of doing this in Unix?

Maybe I should have made the multi-part tar file with the tar program in the first place, but I can't find Windows binaries of it anywhere?

EDIT: Never mind, I just had to get p7zip for unix.