The Dynamic is undoubtedly a Gallus "bakelite." The difficulty lies in distinguishing a Dynamic from a 'normal' Gallus. Therefore, I have labeled it as 'rare' based on its rarity, as I have never seen this model at flea markets, but perhaps I have seen Dynamics, mistaking them for Gallus cameras.

On the catalog page, we can see that there were at least three models of the Dynamic:

No. 1: Basic version with an achromatic lens and P, I shutter, and three apertures.
No. 2: Version with a Boyer Topaz lens opening at f/6.3.
No. 3: Version with a Boyer Topaz lens opening at f/4.5, which corresponds to the high-end range for Gallus.

The Pontiac folding cameras were featured in distributors' catalogs from 1940 to 1953. The period of occupation complicates the analysis from 1940 to 1945, during which there may have been no production, and few sales catalogs.
All of these cameras are 6 x 9 cm format and can be divided into three series.

The first series consists of cameras made of bakelite, which was a continuation of Gallus' production from 1939. This series doesn't have a specific name. These cameras are highly attractive and beautiful, making them popular among collectors. However, the fragility of bakelite makes them quite rare.
There are few models in this series. The initial models are identical to Gallus cameras. The only distinguishing feature between the Pontiac and Gallus models is a plate attached inside the folding door. The bakelite is black, and they feature a simple P/I shutter and an achromatic f/11 fixed-focus lens. The production of these models was very short-lived, possibly due to the depletion of Gallus stock. There's also a version with a Boyer Topaz f/6.3 lens, which appears to be black.
The subsequent models are made of brown bakelite with varying degrees of marbling. The shutter (attributed with uncertainty to Gitzo) is marked with MFAP (Manufacture Française d'Appareils Photographiques). It has three speeds and a B (bulb) setting. The lens is adjustable for focus and can be either a Berthiot 4.5/105 mm or a Pontiac series II lens with an aperture of f/4.5.