Thanks for clarifying that. My test solution was to create a dummy course with only 1 workshop module, back that up, then restore it as often as required. That appeared to work fine.
I could also include one of each module type in the course (all the topics are identical in structure) or better, build a complete base topic in the dummy course (structure without content) which I backup and then restore and modify for each topic in the real course.
Thanks again for your help,