The project became confusing when it came to constructing the soundboard.

Plans (from Roy Courtnall) referred to bending each half of the soundboard in order to create an arch at the bridge position before joining. For me this was an unexpected complication.

Later construction plans available from R & F Charle also referred to a fold (pliage) at the bridge area to create a dome effect.

There is a photograph in "The Story of Selmer Guitars", of the press used for gluing the centre join which maintained the angle of the bend in the soundboard.

There were makers of Maccaferri type guitars on the web and I emailed asking their advice on this point, with due respect for any refusal to give away confidential construction details. I received very helpful advice from each of the makers, and found that opinion was divided as to whether it was necessary to heat bend the arch in the top or to form the arch with curved bracing.
I must give a big thanks to Michael Dunn, John LeVoi and David Hodson for being so openly helpful with their expert advice.

The first time I heard the term "pliage" was on a visit to Paris. I was fortunate to be able to discuss whether the domed front was pre-bent with Madame Charle, when buying a copy of "The Story of Selmer Guitars". She explained that there was a definite "pliage" (folding / pleating) across the soundboard behind the bridge area of the original Selmers she had studied.

Original Selmer Guitars -

The first opportunity to see the inside of an original Selmer was an article in a French magazine -

Guitarist Acoustic #6 (August / September 2005) had a photo-story recording the restoration of an original Selmer (No. 436) but did not describe the original design features.

There were several pictures of the inside of the soundboard, which had been removed as part of the restoration, but unfortunately too small to see in enough detail to confirm a "pliage".

Benoit also has a large section on Guitares Manouches which includes construction techniques.

The Djangobooks Forum has a BYO (Build Your Own) section with advice on making the "pliage":

http://www.djangobooks.com/forum/discussion/17146/byo-my-first-gj-guitars/p2

It seems, depending on who you ask, that there are a number of ways to form the arch in the soundboard -

Internal bracing alone, after gluing the soundboard halves together.

Scoring a line inside the soundboard halves, under the bridge area for the bend and heating, to form a crease (pliage) before gluing.

Heat bending by hand, without any scored line to form a gentle arch before gluing.

Heat bending with a jig, as shown by Michael Collins in his book on Selmer guitar construction.

Removing a tiny wedge from the inner edge of each soundboard half. before joining in a radius dish and go-bars - no heat involved.

Scoring a line and using a ruler and wedge to form a crease, as shown by Benoit de Bretagne.

Any more enlightenment on the construction of original Selmer Maccaferri guitars would be gratefully appreciated.