lowflare,
I've got an operator's manual (about 100 pages of A4) for the GNS-X as fitted to the Avro RJ100.
CityFlyer's first RJ100s were fitted with the GNS-X whilst the later models were fitted with the Collins GNLU 910. Unfortunately for you, most of us prefered the GNLU to the GNSX.
If you PM me with your name and address, I'll send it to you in the post.