Well, as they are the culmination point of a long series designed for 6x4.5, from a maker that made their last 6x6 more than twenty years earlier, we can safely assume that it is no masked down 6x6 camera.
That is, if you really want to convert it to 6x6, you'd have to saw apart two cameras at 7.5mm offset to the left respective right, join the longer halves together and reprogram the entire transport logic within the camera software. If you are lucky, the lens will even cover 6x6 without visible corner degradation. Something like that would be remotely possible, if you have enough cash to burn - a small German company performed similar stunts (with original maker support) joining Contax G1's and Hexars into (very expensive) double-eyed 3D cameras.
