I started with https://github.com/Sensebloom/OSCeleton to connect to Processing, I modified one of these examples: https://github.com/Sensebloom/OSCeleton-examples
and it worked well. Couldn't see how to connect to OSC to Scratch, so I modified the OSC example to send Scratch variable updates. I can email you Processing code if you pm me an email.
My email is email@example.com
Thanks so much!