I have just done / doing this , I have the 4x4 cosworth mastercylinder but I have not fitted the abs block (as I don't want to run it ) and I have just put all the wires onto the master cylinder , I still have most of the wires but I plan to cut out the ones I don't need , sure I seen Ronnie Amis had a loom made up just to power up the master and do away with the abs block, could be worth asking him as I think he knew someone that sold them for around £90