Hi,
I cannot add much to this thread but as long as I know, most sporting guns were confiscated in France by French police and returned to their owners after the war.( at least on Saint etienne area.)
Most of the guns that do not survive the war time were those hidden in the woods. Thats why there are few Ideal guns for selling now.
I reccomend both Mournetas books, the one about the Ideal shotgunand the one on the Robust. This later book have more info about Manufrance story.
Thanks
Martin