Thanks for your replies.
Farms — I’m on one at the moment. It’s a bit of a nuisance because the “horsey” people just seem to park anywhere and don’t realise how much room a truck needs to get in / out. Farmer is a nice bloke and really helpful — I can use power, water, pressue wash etc. But the yard is also “soft”, so its sloshing around in the mud when it rains. Not good at 04:00, and the cab and tyres get really grubby.
I didn’t think of Thurrock. I’ve not been down to that truck stop, but I’ll go and take a look.
I have been offered a space in what sounds like a secure yard. Ex freight operator, about 20 trucks there at the moment. But he’s applied for planning permission for houses, and its likely this would only work out for a year. It must be roughly £600 to change the O’Licence — not sure if it’s a good idea, but it is my banker!