@Tad 

I had a go anyway. It did not work. New router did not allow loading VR600V configuration. It;s a pity as a lot of work had to be done manually. All of the VR600V features are on the VR2100V as well, so frankly, there is no reason why they could not load easily while the new features remain set to their default.

Maybe one day ....

Tad wrote

I am looking at buying a new VR2100V router to replace my current VR600V (no longer available).

Are there any tools which would allow porting the config from old to new router?

Has anyone tried restoring VR600V config onto VR2100V and if so, what was the effect?