Adam,
Thanks for posting those photos.
Combined with Erics I now have plenty of detail to work with.
Johan,
A friend just bought a ZG in 8x64 which has had the bolt knob cut off and replaced with a huge black screw-on ball!!

What a horror!
How could anyone do that to one of these rifles.
Looks like I'm getting the job of making a new knob and of course it would be good to keep the whole bolt handle and knob looking as close to original as possible hence the need for photos.
I have the dimensions and also a tracing from another ZG.
I have a lot of other jobs on the go at the moment and in reality would prefer he gets someone else to do it.
We'll see what transpires.
Thanks again guys for helping out on this.