Tom,
As I understand it a 2-stage spring doesn't mean that there are two separate spring assemblies. It refers to the design of one spring assembly where the leaves are separated so that the leaves take the load in two stages.
If look at the page you linked, you will see a listing for an auxiliary spring, but it only has six leaves.
If my understanding is wrong, I hope one of the more knowledgeable bolters will chime in.
