These springs are dummy - the real springs are in the hornguides. They are visible behind the driving wheels, but not very clearly so I felt justified in simplifying them slighty. To make it easy, they are modelled in a fully compressed position where the leaves are straight. The springs are made from solid with the leaves scribed, using a sharp point in the mill, traversing the table in the x-direction to scribe each spring, and using the y-axis screw to ensure that they are equispaced. Then each leaf is cut to size with a milling cutter.
Driving axle springs
Nick Baines Model Engineering