Subject: Re: Troublesome leaf springs
If the springs have been removed and found to measure different curvatures, that indicates that it is indeed a problem with those springs.
I had new springs made for my LG6 by Paddington Springs; they did a great job, but despite a number of attempts, they never did get the "set" right for my car. To be fair, it is a special, hence the car is much lighter, furthermore as the chassis has been shortened, the springs are shorter.
A long way round in stating that this meant Paddington had no standard to work to; they reset my V12 and Riley RMB springs perfectly.
I took the LG6 springs to Jones Springs, where I expected many technical questions. Instead, he simply asked what difference in ride height I wanted. Not very reassuring...but they got it right!
Rather strange that one spring should sag and not its pair. Perhaps one has been replaced previously. Frankly, especially with both off, I'd ask Jones to reset both of them, having checked they have Lagonda standard spring settings available, and they should have. Or at least ask their advice...if they state the good one is fine, I'd accept that opinion.
Laurence