Thanks, that helps me focus my thinking on what I need to do.
On the clips where I have the source files, the following:
1. On opening titles:
Replace the existing title (simple Vegas Pro “Titles & Text” type) which each have different text with one standardised title
2. On overlay titles:
Replace each standardised title with a different standardised title
3. On end titles:
Ditto.
On the clips where I only have finished HD .WMV files
1. On opening titles:
Add a new standardised title (cropped) that will overlay the old copyright details
2. On overlay titles:
Ditto.
3. On end titles:
Ditto.