Well, the attempt to pair Netgear and TP-Link produced very mixed results. A basic TP-Link unit (single ethernet output) paired with the Netgear straight away. Thinking I was on a winning streak I then decided to try to pair the Netgear with a TP-Link wi-fi unit. The two absolutely refused to talk to each other. I thought about exchanging the Netgear unit connected to the router with the TP-Link to see if I could get the 2 TP-links to talk to each other - but it's Friday and the pub is open......
One step forward, one step back.