I just leafed through my Factory Assembly Manual and it does, indeed, show that on both front and rear leaf springs there are two straps on the rear half of the spring and one strap on the front half of the spring for 3600 and 3742 models.
There is a significant error in LMC's diagram, however. Notice the shock absorber is an MC Escher impossible design. The upper mount is shown on the outboard side of the frame but the lower mount is shown on the inboard side of the frame/spring.
The 3100 shock absorber mounts on the outboard side of the spring and frame. The 3600 shock mounts on the inboard side of both.
