Just clicked over 45,000 miles and spent part of Saturday and today driving around a pay and play site with colleagues from Leicestershire & Rutland 4x4 Response,
https://lr4x4response.org.uk/. (A training session - "honest, Guv!")
The outcome of this is the truck is properly muddy and I will need to find out how to get my rear diff lock to engage reliably. Yesterday the rear locker worked fine. Today, after trying to engage the rear locker about a dozen times, the dash showed "rear locker error" and the idiot light console showed a flashing ! and a red rear locker icon. After parking up, switching off and locking the truck for 5 minutes, the error cleared, so I presume it is not serious. A further conclusion is that the Bridgestone tyres are pretty poor for UK mud - the BFGs are much better.