Roger,
I'm curious about your breakdowns. What kind of problems are you having?
I spent six years building my car with second hand parts. But, I got it running. I had so many breakdowns, Triple A threatened to cancel me.
Since then, I spent 17 years upgrading to the best parts.
Just get it running and drive it some. That will be inspiration to keep going and make it great.
Understand though, it will never be perfect. There is always something that can be better or lighter or stronger. That's why this is a great hobby!
Paul