Hi, i find it easier to source my parts direct from the classic center and i know they will fit. But I guess it's a matter of economics in these tough times.
Yes, the centerr spring must have two rubber pads and depending on the part number stamoped into the spring,there are three different sizes . The thickness of these is important to allow for a soft,medium or firm ride . There are also pads under the springs on the torque arms and the rubber pad on top of the spring is what determines the ride height. Again,those come in various thicknesses to allow for things like options etc.