Thanks!
After multiple re-boots of the Virgin hub I finally got a green light on the main Deco unit! After that it was actually easy to get the others set/up.
Took a bit of faffing to connect the switch and couldn’t work out why nothing would connect and then realised I hadn’t connected it to the Deco!
Got the Sonos re-configured as well.
All seems ok so far. Did a few speed tests and will post those later - first I need a beer!