Well just took delivery of one of these jigs, yet to be tested as annoyingly work has got in the way. However I did set it up on the lathe ans fettle the cutter height etc. I can say this is an extremely solid bit of kit, the custom bracket to fir the VB bed bars is solid and no apparent movement or vibration issues.
I will post some pictures and update when I get to play in earnest with the beastie. Does spheres from tiny to over 350mm, has a carbide cutter similar to the Lyle JAMIESON hollower, and the engineering and fit and finish look to be of a very high quality. Supplied with everything required and allan keys , spare bolts etc.