I became curious and looked through my collection of surplus kits. I found one of these, put out by Ambroid. Looked at the instructions and man that's weak. Absolutely no mention, drawing, or photo of the three window side. That there are 8 window castings doesn't help either.
Mike if you need a set of the leaf springs I can help you out. Over the years they made different versions. One version has one slot in the middle, simulating two sets on leaf springs, and the other has two slots, simulating three sets. Do you have a preference?