Anyway, pretty simple really. Just more scrap wood, a couple of cuts on the table saw (or band saw if you prefer) and some sanding and you're all set.
Here they are, in all their engineering wonder



The nut vise has a little ledge on it (the saddle vise could have one too)

Now just take it and put it in your main vise and work away.

And a newly made nut

Here's the saddle vise in action. See how much angle you can get with this vise. Makes dialing in the intonation easier (once you've figured that out)

That's it. Enjoy.