I've a small experience of speaking to 'young people' about sailing and flying. I think Rat5 is on the right track. a lisitng of dates and people they have never heard of is about as much fun as listening to their parents on the dangers of, well nearly anything. Their attention span is short. You have to catch it or they will spend the whole duration of your talk texting their mates.
What has made people want to do this? So Icarus and Leonardo are part of that. Your own experience of toddling around the Scottish islands neatly illustrates dreams becoming a reality for more ordinary people. The Paul Allen and Virgin stuff tells you those dreams are just reaching higher.
You can add in the 'first' stuff, dates and people only if you have their attention and are perhaps answering their questions
Best of luck!