After a few days wondering what I was going to do about pure data not being in the lucid repositories, Peter (Vasil) pointed me in the right direction.
He told me to look here https://autobuild.puredata.info/auto-build/latest/ and download the latest build.
Just be sure to open the .deb package in the right way and it will install pd on your machine.
The next thing I had to remember was that instead of invoking it with $ pd& in the terminal, it is now $ pdextended&
Haven’t had a chance to play much, what with the Leipzig project, but will happy to have it back!