Help needed!!! What kind of group is this? ~20yr Bianchi bike, Campa group.

I bought this beautiful oldtimer bianchi road bike about a year ago.
It has written the name Record 920 on the frame.
I liked it so much, I took it from Germany to the US when I went there
to write my thesis.
On the way back Delta damaged the gear group in the back.

Before I can start looking for the replacement part I'd need to know
what type/year the campagnolo group is.

Pictures are posted he


http://www.physik.tu-berlin.de/~mxhf...WWW/index.html


I guess it is about 20 years old. There are no catalogs online for such
old parts.
Does anybody know, or know where to start looking, or know where to get
parts even?

I tried shops, I tried Bianchi, I tried ebay.... i think I tried the
obvious things.


Max