I've been in touch with Geoff and also had a full email from Drags. Both saying the same, that one of my centres is the slightly earlier one with tags, but they can be machined off and it is then ok for the 57/58 Huntmaster. I had it in the four-jaw on my Myford this afternoon and the job is done. Now all I have to do is to work out why, when I tighten the centre nut, the hub and the basket lock together when they should be independent. Something not right somewhere, but I've checked and rechecked the order of assembly and it looks ok. So what the..........?