So I completely forgot to get back to this one...yes, the 102 my parents have has the flip up seat. Granted, it's not the original seat but the mounting bracket and such is. I remembered putting wrenches and tools under the seat.
It's just like this picture I found of a 122 off TractorData.View attachment 143526
PACub100 - I enlarged the TractorData pic you posted and the seat support doesn't look quite right. As far as I know the original 122 seat had 2 angle iron supports (running back/forth) and a pin thru them at the front to provide the hinge action to raise/lower the seat. The seat in the pic seems to have a piece angle iron going across the back. Not sure how this would work or how it would actually mount so that the seat could still be raised/lowered.
Kraig - Oh Great One Keeper of the Photos - thanks for the link going back to the rubber seat discussions. Still wondering about the possibility of later production 102's coming with the fiberglass seat like the 122's. And then there is that French brochure - WOW!!!! The 71 has a strange seat with a back support, and the rear wheels look odd compared to the 102 and 122.