Thanks again, Lew. Your arguments are logical. We can think that my exemplar used a frontal stamp that was copied from one rare Godet, and this post-war "maker" decided to create a new back stamp based on the negative frontal stamp. Well, at least my exemplar seems to be a rare copy
BTW, just discovered another strange aspect, the material, it is silver (~800 tested), with gold plating.
rgds
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