Anyone ever see one of these up for sale?
From time to time on Ebay. You may try www.ebay.de or other European sides, just make sure that shipping is tolerable. USPS shipping is sometimes higher than from Europe. By the way, you can get E 636.043 right now.
Thanks for the tip! I checked Reynauld's first, but didn't see it or anything like it, but think I may have found it, thanks to your help. Seriously, I have been hunting around for one since 1975. Seriously.