Seems you got your self a very nice and very important E30 M3 race car - I'm jealous Matt Neal gave me the info I originally posted via his own web page and forum. I guess you could contact him for any info, he sure seemed keen about the car,and as the last person to race it in BTCC, I guess he knew the full history for the cars life.
Do you have any pictures of the car as it was and as it is now ? Would be great to hear some details of the condition you found it in and how it is now.
Thanks to Autohabit/Alan for pointing me back to this thread.
This space is a sanctimonious shit-free zone.