In reply to danielashercohen:
Hi,
actually (thanks to Axel Sherer) I have a solution to make the code originally posted work.
I should have overridden report_summarize, not summarize.
If you do that then you can add a few additional fields / values to the summary which is what I wanted to do.
Kushalmodi’s solution demonstrates how to do far more modification than that if you want to go further.
Dan