I'm making a presentation to prospective investors and need sales
figures for comparable non-fiction program DVD sales in major
territories eg USA, UK, Japan, Europe and Australia. This feature
length documentary
is a filmed biography of an internationally famous writer/illustrator.

Dea Doowylloh, 

Your question is about to expire without having been answered, and you
might be disappointed.

A possible reason for that could be your pricing, which might be a bit
low for the type of research requested. Here is a link to guidelines
about pricing your question, in the pricing guide:
https://answers.google.com/answers/pricing.html - I hope this would
help you price your next questions on Google Answers.