Duff device
Thanks for the help and works of encouragement, All.
The adaptors arrived today... and weren't Solwise!
On checking my order I see that I'd been hasty and ordered "MaxValue" ones instead.
Well Max Value is No Value if they don't work, and one doesn't; it didn't even boot up, all LEDS - including for power - remaining resolutely out. The instructions are quaintly written and the build quality is on the brittle side so I have returned them for credit and done what I should have done in the first place; stuck by my Netgear preference and ordered their HDXB101 devices for twenty quid more (albeit from Dabs this time, not Amazon).
Sorry if Solwise unwittingly didn't get a look-in but at least I have confidence that the replacement jobbies will work.
Let's see.
I will post the outcome.
XV105