I wonder how values will go for diesel non-classic (under 40 years old) Land Rovers with the new "low emission zones" that are appearing all over the U.K.

London is already a no go.
Manchester's clean air zone comes in next year, cars are exempt but all commercial vehicles (any Defender made after 2010 and hard tops, truck cabs, Utilities manufactured before then)
will have to pay £9 per day. The low emissions zone is not just the city centre either, it extends right out to the suburban areas.
Edinburgh's clean air zone comes in next year and all vehicles that don't meet the latest standards (pre 2016 diesels and pre 2006 petrol) will have to pay a daily penalty.
How long before this is the case everywhere?
My 2006 110 Station Wagon is currently exempt from my local clean air zone charges, but if that changes it will cost me £200 per month just to take it off the drive.

Obviously that will mean selling it, the govt are offering "up to £2,500 if your non-compliant vehicle is scrapped through an official channel"
Well that's OK then
l will only lose £15,000

I don't live in or near a city and have no need to go into one. Problem solved

Yes but many do. There's quite a lot of Puma Defenders suddenly come on to the market round here, the local specialist LR dealers showroom is full of them, where previously they couldn't get stock.

As I understand it, it is a nightmare, we have laods of non Ulez complaint trucks, so logically they use them to go to non Ulez areas, but with roadworks/accidents and various other diversions they keep straying into the Ulez and we are getting shed loads of fines!
So it wont just be cars that are in the immediate Ulez, it will also be cars that are near the Ulez.

This is an interesting topic. Even swapping the engine to a Euro 6 compliant unit or full electric conversion will not help under current ULEZ rules as the original factory specifications are used to classify the vehicle. A change in this rule would at least allow an incentive and an upgrade path for owners and stimulate the market for conversions.

it is not just the UK. Major European cities are doing the same. I fell foul of the Antwerp city emission zone when diverted through the City Centre by Waze due to congestion on the ring road. I ended up with a fine in the post a few weeks later.