nothing that ever made it to production if they even bothered to get one on the drawing board..
i suspect it was just put in the too hard basket vs what it would make ($) them in return when you consider what the other makers already had on the market in the way of coupled 6x9 RF . the Bessa II was still being made and is overall a better camera and was outselling the S/Ikonta C by enlarge in the mid 50's, luckily for Voigtlander they had a good design to start with, then in late 50's they offered it w/APO lens for the pro's, to make it even more attractive. interstingly you notice that Voigtlander had the market share for coupled 6x9 RF but left it to the others makers including Zeiss Ikon for the coupled 6x6 RF market share
the Ensign Autorange 820, a fine camera except for its inferior shutter, was also available in the late 50's. Ensign put a great deal of money into the development and production for that 6x9 folder(albeit a few years too late), they had some kind of passion to want to build the ultimate folder, which, most likely was their (Ensigns) ultimate undoing!; they really should have sunk the money into TLR/SLR from a business POV although today we are glad to have the quality 6x9 folder to use, if you can find one for the price of an arm or leg....