Thanks all, got one locally that seems to work. My issue, as far as I can tell, is that one of my original Wemos boards was pre- flashed, whereas I had to flash the firmware to the other one.
Here is the brunt of my post. Being a total analogue brained computer luddite, with Mac only experience, I was dreading this process, but in reality, once I remembered that I had an old Win laptop, I managed to get all 3 boards up and running the latest firmware revision. It did take about 4 hours of trial and (mostly user...!!) error, but the satisfaction having achieved it was immense.
I won't go into all the steps I took, as most of them were unsuccessful, but the point is, that if I can do it, ANYONE can, there are plenty of resources online to guide you. (Admittedly some more useful for idiots like me than others) but a couple of hours with a PC and a tablet or phone to look up online guides, and you too can do it!!
Now to activate my Ubidots account and get my codes to register the devices, and away we go!!
Have a go!!!