Though NLA in Europe, because the early Audi 200 was sold in the USA as the Audi 500 there are still lots of spares available there (they sold 85000 in the USA). I found a terrific website called
http://www.rockauto.com who sell almost any spare for any car - really amazing! So have ordered a LH and RH hand brake cable - expensive postage but don't forget $2 to £1 at the mo!