Thanks DIYMum. Your posts have always been a great source for me

but I am glad it is over for me (for now). Those sheets you produced are great !
Just to add, that there are a couple of apps out there that are helpful with the 3D aspects: there was one called 'cube it' and another called 'toy blocks'. The first one gets you to add or delete cubes to make the diagram and I used the second one to to help DSs visualise diagrams such as yours as you can move it around and see it from all angles (so you can hover over the top and see how a plan would be drawn etc). I found these helpful and fun but of course you can just use the old-fashioned real toy blocks!
I would also caution the CEM NVR is very tight on time: around 24 questions ( different types) in 7-8 minutes. In our case I found that DS was getting 85- 90% plus during the standard times allowed but when I restricted the times and got him to cover several types within the short time, his marks would drop to the 50s. I would say practice different types to get the techniques right but towards the end they really do need to build up speed.
UmSusu