SunTour used to stamp a small M on the body where a freewheel tool would engage to indicate Metric/French. I have at least one of their Perfect freewheels like this. I assume they would also do the same on the later Winner freewheels like you have posted, but do not know this to be the case. I have also seen Perfects with Metric spelled out and with 34.7 x 1.00 notation in that same location.