I first became aware of the 2X3 inch format (as it later became generally known in the UK) when my Grandfather gave me, circa 1947 , a blue Ensign E29 Box Camera and that was followed some time later by a Krauss Rollette. It soon became apparent to me that the format was already semi-obsolete but I did not uncover its origin until about 2000. I still have the box camera and black and white roll film was available for it from one UK maker (Standard) until about the mid 1970's. Kodak ceased production very early in 1951. I believe that the popularity of the format went into decline in the early 1930's for a number of reasons including the greater use of 127, pushed by the formidable Kodak marketing organisation, and perhaps even more importantly the introduction of cameras that permitted 16 exposures to be made on a standard 8 exposure 120/620/127 roll. The growing presence of 35mm cameras cannot have helped either. I have found only one 129 size camera maker (Welta) that offered a comparable facility. Some versions of their 'Perle' (5X8cm) folder gave the user the option, by use of an internal mask together with a second red window in the back , to produce 40(?)mm square negatives. I conclude that by this arrangement it was possible to make 11 negatives on a standard 6 exposure(it was never more)129 film.
Apart from Houghtons many other European camera makers offered models in the format. They were almost entirely German as their camera industry was the world leader for many years. Here are some names: