Seeking some advice. Can anyone tell me the threading on the dipper tube for a 1st gen Pavoni? And/or if it is the same as later models?

Cheers!

I can't answer the threading question but trust that you are aware that replacing the dipper tube requires removing the group, which is a difficult task but can be done. I document that process in my restoration of my 1961 La Pavoni Europiccola. If you don't have to remove the dipper tube and can leave the group in place that is much easier.