I was fortunate to acquire a pair of very early Campy rear dropouts recently. Here's a picture.
http://www.velostuf.com/
Note:
1) the open "C", 2) the "BREVo" (this is a contraction of "BREVatattO" I think) 3) the large diameter adjusting screws 4) the lack of knobs on the end of the screws- there's a slot for a screwdriver instead
Also, I have a used Sturmey Archer 1954 ASC hub for sale on eBay,
John Barron
Minneapolis
http://www.velostuf.com