I really like those purpleheart lams the way you have them.
 
The DW body style isn't my personal favorite, but this is certainly cool.

Rob,
fantastic!!!
Could you put on the bridges and knobs like on my DW TFJ?
Maybe an additional selector switch for the both necks?
What about the necks? 4string fretless on top and 8string below?
Maybe the 8string with a longer DW headstock to fit the 8tuners.
Maybe 4 big and 4 small?
 
You are great man...
Oliver (Spyderman)

Wow Rob,
 
Perhaps you can work part time for Alembic.  That looks exquisite... and very, very expensive!
 
The Doubleneck actually makes sense with that body style. That upper portion of the wing would help with the balance. I'd go with a fretted 4 lower neck and a fretless 4 upper neck. I'd also try to get the necks still more parallel.
 
It should be player friendly as well as being a beautiful work of art.
 
My 2 cents,
 

Oliver. Work in progress... patience.
 
How about using the standard(DW) headstock on the upper neck, and a mirrored on the lower.
That would put the bass tuners on the outside, then the smaller (shorter) guitar tuners end up on the inside.
Skip the bevel on the side of the lower peghead.
 
No difference in size for the -heads.
 
Can someone give me a blueprint for the knobs and dials?

Rob,
sorry, didn?t want to push you. I am really happy about your skills With the headstock will not work as we need e/E a/A d/D g/G so I think we must mix between small and big ones.
 
Oliver (Spyderman)

Rob,
thank you so much.
Have just sent a mail to Mica and Susan rgdg a definite estimate.
So I hope we can turn this beast into reality (and you will have fun with this too)
Cheers
Oliver (Spyderman)

Ovals in place.
 

Rob,
you are quick as hell. A real CAD master.
BTW I have decided only to take three stringers for the neck throughs as on my DW Tears for John.
Cheers
Oliver (Spyderman)

Considering that You are getting this as a double of the bass You already have, I understand that.
 
Do You mind if I keep the fading out PH lams on the renderings?
I think the three simple ones look ... boring.

Mica. What are the diameters of the drills used to make the pockets for the string ends in the tailpiece?
Do you use the same size when it's a octave tailpiece?
 
And what is the stringspacing between bass and octave string. Thanks.

Rob, of course. No problem. I once had a Spyder 8string, here are some pics to give you an idea on string spacing. On this one, the pair of strings used a tailpiece together. So I don?t know, what Mica would do on the DDW? Double slots or using one slot for two strings?!  

 

 

 

  Oliver (Spyderman)  (Message edited by davehouck on August 10, 2008)

Hey Oliver,
 
I personally don't like the look of two strings sharing the same slot.  It takes away from the detail of the Bass.  That's the only thing I don't like about the 12 string Baritone Guitar.
I would also bookmatch the tops and backs to center - I'd rather cover the neck.
 

This tailpiece uses individual holes, image in Mica's post #5272.
 
http://club.alembicguitars.net/Images/631/14858.html?1179778327

Rami,
I think they did it on the Spyder as there are only 4 single tailpieces. Generally, of course, it looks better.
The top on TFJ is also bookmatched, of course, but I personally like the look of the neck through, this is classic Alembic.
Oliver (Spyderman)

I agree with you Oliver. For what a custom instrument costs, it is 100% about personal preference.
That Spyder 8 string is just beautiful beyond words. A very unique instrument.  
 
Rami