No idea how such a guesstimate would be determined, but we can see a steady rise in prices as one indication of sustained and growing interest in vintage ZM and Ulm Walthers. Likewise, Manurhin prices are rising, which suggests to me a second-level knowledge about post-war Walthers. I would guess that those buyers are not predominately people raised in the post-Wonder 9 era, but perhaps those folks are actually more appreciative of old-school quality once they get more educated. My entirely uninformed $0.02 