Definitely Croce d'Aune. Croce was first intro'd in '87, and the linkage was upgraded to the criss-cross one in either 1990 or '91. So yours would be 87-89.
Delta prices are all over the map these days, and I'm loath to speculate. I'd start them low, and see where they go. I'd guess that $300 would be the upper limit for a Croce d'Aune set, but who knows -- a decent looking set of calipers just sold for over $200, albeit with the newer linkage.