For several years in the late 70s all Peugeot Mixte bikes delivered into the UK were equipped with HELVETIA model bars.
Thes in plan view resemble porteur bars but are slightly wider and taper slighlty outwards at the grips. Additionally instead of being flat they drop away by about an inch or, if reversed they rise by the same amount. The bars were generally mounted on relativelt short, around 70mm, ATAX stems. In this way thew grips reached well back from the centre-line through the bars.
The bars proved unpopular with UK dealers so the bikes were euqipped afterwards with either Allrounder straight bars or drop type.
I ride with the Helvetia bars in their proper slowing down position and find them extremely comfortable. Of course I hace CLB reverse brake levers stuffed into the bar ends.
Norris Lockley
Settle UK