Hi Stuart, welcome to the forum.

I also have a 260VMC at my local hackspace (http://rlab.org.uk/wiki/Boxford_260_VMC). Its in pretty good condition and runs with the full Boxford PC software. We haven't been able to find any decent documentation either though I'm afraid.

We are still deciding if its worth converting to Mach3 (if it wasn't working it would be an easy decision!).

Cheers,

Jim