I'm wondering if it's a reasonable thing to do to duplicate my worldspace so I can have the effect that the player can return to a "different" landscape after it has been nuked? I had thought just to have a trashed versions of the buildings etc, but then I realised that I could have a LOD issue not matching the new look buildings(well what's left them anyway).

Any thoughts?

Also I haven't looked into LOD generation for FONV but I have generated it for a wordspace I created in Skyrim using Oscape with good results, would the same / similar process work with FONV?

Thats good thinking to end up there ...

See what happens.

Lod ... yes it exists

I don't know how Skyrim did it, but I found the Fallout method to be a major pain in the butt. Yes it is possible but you'll need to jump through hoops in order to accomplish it. For the record, I could never get it to work, even though all I was trying to do was give the Bigtown houses a VWD view, something the developers forgot to include. Granted that was in Fallout 3, but since New Vegas uses the same basic engine, I suspect the process is the same. I could very well be wrong on that account though.