It's taken nearly 3 years, but I think I have the answer at last... To complete the sequences requires the following numbers:
To explain how, I'll take you through my solving process in order...
Step 1a: The names
The first thing that jumped out at me on seeing the names was that:
Step 1b: The number of terms
At this point, looking at 'Harry' I noticed ...
The next number is:
Here is the process to transform a number to find the next one in the sequence :
Research process on paper: