A colleague suggested that the best starting point would be to use a free online service to prepare 'auto-detect' subtitles, which could then be proof-read and edited before being exported and attached to the new version of the movie for Amazon. This seemed like a damn good starting point. It worked! Well, it sort of worked.
Lottie has been with us now for 5 days. Perhaps I am slightly delirious from lack of sleep but I have fallen for her very heavily indeed much to the delight of my family. That's quite fortunate really as I'm discovering that puppies are not a walk in the park (excuse the extremely weak pun, I plead exhaustion).