This is the front LH spring seat which has a definite break along it due mostly to corrosion. The breal is on both sides of this seat. The other three seats on the vehicle are sound.
I put the Defender to a local who knows about this sort of thing but was told that the chassis leg was also corroded where the new seat was to be fitted and would require plating. Fortunately a friend recommended someone who has carried out this work before and he managed the job in less than a day.
New seat in place and chassis repaired and painted.
Of course we had to take it out for a wee test drive :)
I nearly forogt, heres the video I made explaining difflock.
In a nutshell the four wheel drive will drive all four wheels.
If a wheel is off the ground or on a slippy surface it will simply take the power you are delivering and spin.
The front wheels are locked to the rear so their turning speed is locked together.
If a front wheel is slippy or airborne it will not spin unless one of the back wheels is able to spin.
This can be a great help but you can easily get into situations where both front and rear will spin, but it usually means you are having fun :)