Thanks Bruce - it looks much the same as many other Rovers of that era, at least in the area we are concerned with.

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The area in the red circle shows the cutter disk and how it is mounted. At this point I don't understand how Item 24, the disk boss, works and how the disk mounts on it. Also, there is no reinforcing washer underneath the disk, but the disk shows an un-pitted area the size and shape of such a washer on its underside. As Julius Sumner-Miller liked to say, "Why is it so?"