RMAN backup using incorrect Networker Server address

Hi All 

We have recently installed a new Networker 19 installation on Server "Y" to eventually replace an old Networker 8 server "X" . I have installed the 19 client and NMDA software on a set of  OEL db hosts and backups are working fine. However when i try to restore to clone from Production the rman script fails saying it could not locate the backup piece on server "X" . Server "X" being our original Networker 8 server. 

To the best of my knowledge server "X" was never configured on these Linux hosts so I dont know why its looking on this server. 

In the rman script i have used the following lines to allocate the channel. 

ALLOCATE AUXILIARY CHANNEL CH1 TYPE 'SBT_TAPE';
send 'NSR_ENV=(NSRSERVER=Y,NSR_CLIENT=hostname)';

server and client details anonymised. 

I have checked /nsr/apps/config/nmda_oracle.cfg , thinking the old server might be stated there but the file is just as default. 

Does anyone know why the channel is set to the old server?