What about the Campy Record cantilever brakes?
Campy made at least two versions of canti brakes, one set was black, designed for MTBs. The second was a road set, designed, I believe, for tandem use. I could never get the latter set up well enough to actually use on the road, so I ended up with Pauls on my Campy 'cross bike. And I didn't really like the MTB version. too Shimano-like. :)
I think the Record cantis are probably more rare than the Deltas...but I'm guessing.
Lee
>From: Peter Koskinen <prkbikes@bellsouth.net>
>To: classicrendezvous@bikelist.org
>Subject: [CR]most rare part
>Message-ID: <CCEEBDED-822B-40D4-8F31-6CB1DE23988F@bellsouth.net>
>Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
>MIME-Version: 1.0 (Apple Message framework v915)
>Content-Transfer-Encoding: 7bit
>Precedence: list
>Message: 3
>
>Bruce Thompson says: Campy Delta brakes. I'll up the anty on that
>line. Campy Delta brakes in current use? Personally I own 5 sets and 3
>sets are in current use on daily rides.
>
>Cheers,