I sure did, Steve. He was my mentor when I started collecting. Visiting him in his beautiful flat in the very center of Paris, next to "Hotel de Brienne", where the Ministry of War was located in WW1, was quite a treat (I have attached a picture of this building in August 1914, with the first flag taken to the Prussians displayed at the window. More trophies were exhibited, which attracted a considerable crowd).
The way his collection was displayed was exquisite, notwithstanding the intrinsic quality of the objects.
He was of course unbelievably demanding when it came to the quality of helmets. My first experience with him: I coveted an UR14 officer Tschapka that was for sale privately. I managed to borrow it from the seller and rushed to Didier's place to seek his opinion. He looked at it and went: "Undoubtedly original, but what a piece of shit !!". Retrospectively, I realized that the Tschapka was indeed a little battered, although it would probably cause much joy to many a collector nowadays !
I own two helmets from his collection, one of which is pictured in the book discussed in this thread.
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