Hi,
Looks like Auto Surplus has come through with new grey motor Oil Pump kits,
They are now on Ebay http://www.ebay.com.au/itm/Holden-Grey-Motor-132-138-Oil-Pump-Kit-1948-1963-OPK221C-/281588056926?pt=AU_Car_Parts_Accessories&hash=item418ff4c35e (http://www.ebay.com.au/itm/Holden-Grey-Motor-132-138-Oil-Pump-Kit-1948-1963-OPK221C-/281588056926?pt=AU_Car_Parts_Accessories&hash=item418ff4c35e) at $190 inc postage.
Cheers,
Trevor_B