In the TECHNIQUE menu, in Writings and Images about Scuba Diving History this month we publish La Spirotechnique "Les Scaphandre Cousteau-Gagnan" manual, edited after the CG-45 regulator presentation in 1946. At page 14, you see its circuit diagram where inhaling air runs to the left corrugated hose and exhaling air runs to the right, therefore inverted compared to what we always saw in these company’s units. A mistake? Impossible. Maurizio Baldinucci gave me the explanation, always an expert concerning historic regulators:
"At the beginning, CG-45 regulator rotated of 180 degrees compared to the current one, with the consequent inversion of inhaling and exhaling corrugated hoses. To improve the way of the discharge corrugated hose, the respective collector (originally screwed to the regulator body) was folded towards the rear part, as witnessed in the few pieces still existing, owned by collectors. After the first two years of production, the regulator body was oriented in its final position".