Hi all people:
I am a new member of this group, and take this moment to include a
more detailed information about the photos of my instrument just
posted in "Photo Section" of this group. It was a surprise for me to
see a work done by another guitar aficionado instead of me.

11-Strings Alto Baroque Guitar (Altgitarren)Description:
The 11-strings Alto Guitar (Alt Gitarr, Altgitarren) was first
designed by the Swedish luthier and acoustic researcher Georg Bolin
and his friend the Swedish lutenist-guitar player Per - Olof Johnson.
They developed a new instrument with a more short neck (like the
Requinto in "g") but with the (from the trebbles)
1st to 7th strings with the same lenght, and the aditional basses
with different and more longer lenght.  The 1st string is tuned "g"
and its lenght stopped at the 3rd fret.
11-Strings Alto Guitar, (Altgitarren) Intonation, (from 1st to 11th
strings): g1-d1-a-f-c-G-F-E#-D-C-B.
With this intonation you can play lute music direct from the
tablature.
There are others possible tuning developed by different players who
tunes the aditional bass strings to the key.
Inspired in the Goran Sollscher Alto Baroque Guitar performing of the
Bach's lute music and with invaluable information I could find (By
the '80) in Gendai Guitar Magazine I built this instrument but with
some modifications to the original Bolin's design:
-a little more smaller soundbox.
-a more reduced string lenght.
-a 12th fret-neck junction with the body.
-a rather different pegbox and cut-away.
My first 11-string Alto Guitar:
http://rodolfocucculelli.8m.com/html_docs/ing/galerias/galeria04.html
  
The woods and details of construction:
Scale lenght: 1st to 7th string: 55,05 cm.
Overall lenght of the altgitarren: 92 cm.
"Plantilla": R. Cucculelli.
Top: Alerce Patagonico (Fitzroya Cupressoides), Patagonic Larch.
The rosette is oval, handmade, with mother of pearl figures inlaid in
a black ebony mastic.
Soundbox measures, lenght: 41,3 cm.
       upper bout: 25,7 cm.
       waist: 21 cm.
       lower bout: 35 cm.
       soundboard depht: 98 mm, 105 mm.
Bridge: Wenge (Milletia Laurentii)
Strings spacing 1st to 11st string: 11,6 cm.
Saddle: Bone.
Cut away: Broad, considering the size of the guitar, to let a free
access to the highest notes of the fingerboard.
Neck junction with the sides: 12th fret.
Back and sides: Indian Rosewood (Dalbergia Latifolia), bookmatched,
with a center strip of American Oak.
Purfling: American Oak.
Neck: "Cedro de Oran", (Cedrela Balansae), with two truss rod
adjustable from the soundhole, to control the action of the strings.
Neck thickness at nut: 17 mm.
        at 11th fret: 19 mm.
Nuts: Bone.
Strings spacing at nut 1st to 11th: 80 mm.
Fingerboard: Brazilian Rosewood (Dalbergia Nigra)
Wide of the fretboard at nut: 89 mm.
      at 12th fret: 109 mm.
Frets: 22 frets from the 1st to 7th strings nut. Total frets: 28.
Nickel, tall, narrows.
Headstock: Veneered with Ebony. A very reduced neck to obtain a less
heavy neck.
Heel: Own design, strongly inspired from the work of Maestros Joaquin
Garcia Fernandez and Juan Morando.
Tuners Schaller, gold. 
Varnish: Shellac.
By the moment I do not have a mp3 file of the instrument. But more in
advance I'll include it.
I hope you liked the instrument.
If any aditional information is needed, no doubt to ask.
My best regards.
Rodolfo Cucculelli
Via Dante Barbano 20. Cella Monte
(15034), Alessandria. Italia.
0039-3286444321
http://rodolfocucculelli.8m.com
rcucculelli@...