Well they do tend to corrode between the leaves and that corrosion dries out then starts to jam the movement of the spring. It is important that they are kept clean and lubricated. Soak in penetrating fluid and bounce the car up and down... quite a lot and you will see loads of rusty fluid being pushed out. do this several times and when the exudate starts to show non rusty dry then down. Now new springs are greased, some cars have nylon interleaves, Morgans don't. I have tried greasing between the leaves but the spread wasn't good enough so I reverted to a heavy oil. I have an old spring spreading tool from the times when these springs were commom fitment but there isn't enough room to use it! I tap an old screwdriver in between the leaves just enough to slightly part the leaves and squirt the oil in. You don't need loads its the getting it in that matters. When you remove the screwdriver it spreads the oil along the length for about 6" so repeat along the length.
No back to bouncing an you will notice a big difference. stand back and see if the car is sitting level, it probably will be. when happy an old brush and some oil to paint the outside of the springs is a good way to put an annual hat on them!
2002 was not a year showing as having poor made springs, 2011 -20013 were the dodgy years and yours has OK milage. I can't see your car's stance or the detail of the springs but I wouldn't be surprised if they just need a clean and re-lubricating!
