Thanks for all the input.
I sorta combined a few ideas of mine and your advice.
First I made a small face plate to hold in the 3 jaw, it's rough but true, and I marked #1 jaw position on the shaft.

Then a block of pine, the work piece and a largish washer.

I put my cross slide stop on and set it to the diameter I needed.

I then attacked it with this little tool, which I seem to use a lot.

That worked well and I soon had a nice circle.I drilled 2 more holes and bolted the lot together.(and forgot to take a photo

) I could then remove the centre bolt and finish the job with my holesaw.

Now a bit of a rub on the wire wheel and I have 1 ring, 7 to go.


Thanks.