Land Rover NRC 8044 and 8045 coil springs.

A kind soul has measured these up.  They have 9 coils each using 15.2 mm bar.  The lowest two coils are at a tighter pitch of 27 mm  with the rest being around 47 mm.  I calculate this gives a rate of 155 lbs/in up to around 84 mm (3.3") of compression and then increases rapidly to 215 lb/in as the lower coils touch.