Firebird 12-string neck specs

[Rock LaVerve]

I recently acquired a '66 Firebird V-12 which had been tragically converted to a six-string. I've had the most obvious of the mods reversed: nut and bridge (new), tuners (vintage), new slide switch where the original once was, and plugged the holes where two (two!) replacement toggle switches had been installed. A middle mini-humbucker had been added, and I can't remove that without a replacing the pickguard. Besides, that's the one mod that I actually like - awesome tones).

 

But the most egregious molestation was shaving the neck to the point where it is almost uncomfortably thin. My luthier says he can build the neck back up with epoxy or fiberglass or some such magic potion, but we don't know the original dimensions. The thickness can be guessed from what's left: near where the heel used to be you can see where the shaving started. But it's the width that's the real mystery. It feels and looks quite narrow, but if it were narrowed from the original, someone did a really good job of trimmimg the frets and fingerboard because they look untouched for all we can tell.

 

Which finally brings me to my question: can someone tell me how wide the neck should be? And if I may push my luck, what about the radius? I'd love to get this baby as close to its original glory as possible. A neck "fattening" would go a long way to that end, but I don't want to do that unless it is true to the to original specs, and I don't know if I want or can afford to do that if a refret is involved.

 

Thanks in advance for any help you can offer.