Earliest Diamond Disc Reproducer.

[Lenoirstreetguy]

I was sorting a batch of phono publications and ran across this issue of the Antique Phonograph Monthly from 1979. In it Ron Dethlefson presented an interesting article with illustrations concerning what he considered then to be the earliest form of the DD reproducer and he's probably correct. My question is : have any of you folks ever seen one of these? I haven't, and I've kept my eye peeled ever since I read this article in 1979. The earliest examples I've ever run across always had the screw plate reproducer. I hadn't read this article when I saw the early A250 that record guru Bill Bryant owned. It was the one that was full of the earliest DD's in the boxes and which must have been one of the first to leave the factory. But I think it had the screw plate reproducer.
Jim