Used UUCP a lot back in the day to push software updates out to customer machines over dial up.
Sometimes I had to uuencode the x86 binaries and send them via cu when uucp wouldn't work (chat scripts were often tricky to get right).
UUCP was handy because you could push files and run remote commands on a batch schedule without a lot of scripting. We did have some clients that had more complicated setups where we would have to resort to SLIP (serial line IP) and more traditional scripts/rsh/etc. All terribly insecure, with plain text passwords in files...or worse, ".rhosts" files.
All the code was written as a combination of Microfocus COBOL and hairy shell-scripts. I recall we had a lot of random SSH-tunnels being held open via keep-alive-pings, and SLIP was definitely something I had to use.