well thanks for the help
Anyway Jimmy Stone tells me that although SBR no longer use an electrical diff pump, they used to use the VDO and he considered it very good but expensive. He also suggested removing the internal filter screen if another filter is in the line b4 the pump.
More importantly, the Redline Distributor told me NOT to pump their Shockproof oils as the oil will progressively thicken and stuff the pump and lose lubrication effectiveness.
Therefore, no pump and filter on this diff!