Wow this is really great stuff! I knew nothing about making a custom career before so this provided a great template that I could tweak to my liking.
I noticed this doesn't include the Canadian GP that took place in 1967. There is actually a mod of the Mosport Park circuit available on RaceDepartment. While it is a modern version on the track, the actual layout has not changed since 1967 so it suits me fine.
Also for personal taste I decided to swap out the French GP to Rouen Les Essarts and double the amount of laps for each race to 20% of original length, but that's just me.
The Mosport Park thing and the French GP was mostly just done to my own tastes, since I wasn't planning on releasing this initially, but I'm glad that you're tweaking it to your own liking!
That's what modding is about.