I have just bought a Nesor Centrifugal Casting machine, model E4,
on E-bay, by the way I am in the UK, and I am now looing for some
crucibles of the right size.
If it's like mine you will need to look at the base, to check it
will slide in snugly. I got mine from a dental supplier, a long time
ago, it might be worth trying that route. (I'm in the UK.)