Our beautiful ford Duetto has been stolen!

Like JT , we have been looking out for any sign of your Duetto, seen plenty of older ones this week.
Sadly I concure with others that your van could be out of the U.K or stored in a barn waiting to ship inside a artic trailer , via the dockyards.
Hundreds of plant and farm machinery are stolen and shipped this way.
Really gutted for you.
Boaby pitched in sunny breezy Whitby

Did it have a tracker, either a commercial one or a self-fit GPS device like the TK104

I don't know whether a GPS tracker is worthwhile though, as it's likely that any knowledgeable thief will have a £10 GPS jammer with him anyway. If you didn't know, these have a huge radius of interference, of about 100 metres to nearly a kilometre, if you've ever lost your sat-nav's GPS signal for a long stretch on the motorway, it's possible that there's a truck driver, rep or thief driving along near you with one running.

I have an IP camera with instant alerts to my phone/tablet/email to warn me if there's any interference with our van while it's parked at home, but one of my fears is coming back to a French car park and finding it missing with all our belongings/clothes/tech/money/bikes etc.

If we get another Motorhome, I will fit a hidden switch to disable the ignition. Also fit an alarm to sound if the handbrake is released, if the switch is not set. THis was on my to do list. A bit late now I know, but I don't want to go through this again.