Do you have photos of everywhere!? Very handy
I think a lot comes down to determination and ingenuity. So many bits are still available and there are also welders and such who are very capable. It may not be 'factory' and the PCGB may not approve but the car would still live on! Maybe it comes down to the person and how much they want it to carry on, and how much they can afford? If you bought one thinking it was a cheap performance car maybe you would just weigh it in for having dead suspension or a blown turbo?
Frankly I am amazed how determined these cars are to carry on - mine needs work frankly but is managing 50 miles a day or more, gets blasted around the country seeing people, carrys bikes, has helped us move house three times. It even got me to work and back consistently in the snow

I know big works looms once we finally by this bloody house!!