Yes, Fred has been good to his word and sorted me out with some replacement bits including completely replacing the 1204 screws which had the slightly wonky end machining - you can't fault the guy's service, 10/10. Regarding the grease, looking at the specs Hiwin recommend, I've realised that I already have something that should do - Mobil 1, which I bought for re-packing the struts on the car.