jimc,
I had a look at the free videos of that whole project, and have got some good help from them. It seems that the new "Gumball" facility in Rhino will be of great use. It reminded me of the way Sketchup works. I'll have to try to produce a decent set of 3-views to make a start. I can do the side and front views, but the plan view will take some thinking about.

LamdaFF, please check your PMs. I've sent you an important email.

OME