Very loosely based on a true story
A quick search on the web reveals Gerhard Zucker to be a bit of a shady character - and possibly not much of a scientist. Even the nature of his death is not clear - some accounts say he died in 1985.
So what? It's still an enjoyable film, although a bit slushy for my taste (even though I like a touch of romance). I rented it because I love the Scottish Islands - and there are some good scenery shots (e.g. the shoreline at dawn when the commandos come ashore).
Interesting that there was such a delay between filming and release - that's the movie business, I guess.