When we took in hand this beautiful folding camera, we say that identification is going to be easy, as a nameplate engraved with the name of the old company Carpentier-Wayant - Paul Maitrejean successor stipulates "Fabrique d' Ebénisterie Photographique 16 bis rue Gasparin Lyon".

But after information have been taken It seems that the company  Carpentier-Wayant-Maitrejean has not manufactured much, or at least has left few traces.
A second track is given by the lens: an E. Suter Anastigmat série I, 1:6,8 F=135 mm. Indeed, we find in a catalog of the "Grands Magasins du Louvre" dated 1913 a very similar 9 x 12 folding camera.

But then again ... Suter was optician, and nothing says that he ever made the cameras he sold under his name.
It was by chance that I couls find the (very likely) real manufacturer. Several such very similar devices have appeared on the forum of this excellent website (...) including one showing  on a ivory plate within the enclosurethe inscription " Bülter & Stammer Hannover ".

So we come to the Zweiverschluss-Klapp-Kamera 9 x 12 dated 1911 in the McKeown, pictureis identical to that of the Suter folding of the Grand Magasins du Louvre! However there are some differences from the original considered here. The most visible are de setting of the rear shutter.

At this stage, I have to tell you that this camera has two shutters, which the German speaking specialists could feel from the model name ... and that is quite unusual.
One central shutter, is mounted on the optical block and habitually allows relatively long exposure time of 1 sec to 1/100, plus B and T. The other is at the rear, it is a focal plane shutter which can adjust the tension and the spacing between the first and the second curtain. The speeds thereof are more difficult to know, but in theory shorter than those of the central shutter.

The plate thus allowing the tension setting appears rotated 90 ° compared to that of the catalogs prints, and the release lever looks different. It is undoubtedly this lever, which has a locking pin occupying the space down, justifying this offset mounting.
 As we saw, the lens is a Suter, so different from what bulter & Stammer proposed.

Here is what is most likely:
Monsieur Paul Maitrejean bought anonymous bodies in Bülter & Stammer, and hardware that goes with them. He took advantage of the trip to buy Suter lens. It is on the way ... In his workshops in Lyon, he assembled all this with a homemade modification of the central shutter to justify his sign "Fabrique d' Ebénisterie Photographique". It remained only to screw a plate engraved with the name of the company  "Carpentier-Wayant-Maitrejean".
 It is in any case a "small format" camera - for the time- rather sophisticated and unusual because probably dedicated to demanding customers (!): Double shutter, triple extension ... the price was to be quadrupled! Simple photographer, please refrain!
The shift is possible, both horizontally and vertically. The front shutter is an Ibso from Alfred Gauthier, released just a few years earlier (1908), with pneumatic brake.
The focusing is done on ground glass, but a folding viewfinder is on top, allowing for more dynamic shots. Just beside, a spirit level is the natural complement to the tripod socket (large thread) for a perfect level adjustment .