Thanks for the reply...
So we have TV running on all machines
And to get a client machine up on the master, we use the master PC to TViewer into the appropriate client machine.
I can see how this'd work, but my only concern would be speed - i.e. to have to take control of the master PC, login to TViewer and wait for it to connect it. Would much rather a solution where we can flick a switch on our client PCs and it instantly display up on the display monitor.