ps2cho:

"Does not raise rear with weight
Manually moving SLS valve does not raise rear
SLS fluid IS flowing as I removed return and it was moving
No leaks in the system"

Given these statements, consider making the leveling valve your first area of attention. Loosen the output line(s) to the struts/accumulators, and check for flow (not just residual pressure) at that point when the valve is manually moved to the "raise" position. It will be necessary to have all load off the struts when doing this, and any residual pressure released. If there is no flow, investigate the valve. If there is flow, suspect that the pump is either worn internally, or the pressure relief valve in the pump is opening at too low a pressure.

The condition of the accumulators is a real but secondary matter. Even with defective accumulators, the system should raise and lower the car.