Having used this excellent site and it's Brain Power of it's readership to track the illusive history of my Lola Peter, suggest a lot of pictures will help kick things off.
I know there is a good spares supplier in the UK, don't know their name sorry, but they might have some info.
Several Ralts came onto the UK hill climb arenea over the last 5 to 10 years and there is a hill climb focused forum called Uphillracers.
You may want to try a parallel thread there too?
Good luck. I was successful getting the history on my car, but it took a long time. People on here are great.