David is correct that there was a Zeus post made for the sole purpose of mounting an Idéale saddle with the flat aluminum girder rails. The cradle parts were modified to fit the girder rails and, of course, would interchange with the Campagnolo parts they were so slavishly copied from.
However Art Stump, semi-famous, West Coast, SoCal frame building demi-god (with a wink to e-Ritchie), made some custom machined from aluminum fittings that allowed one to bolt the Idéale 90-IR to a Campagnolo Record seatpost. Alas, they were never available in your local bike shop. They dated from the early 1970s light weight craze period.
Chuck Schmidt South Pasadena, Southern California http://www.velo-retro.com (reprints, T-shirts and Campagnolo Timeline)
> I believe it was a complete post, not conversion parts, and was made by
> David Feldman
> Vancouver, WA
> ----- Original Message -----
> From: "Mark A. Perkins" <firstname.lastname@example.org>
> To: <email@example.com>
> Sent: Tuesday, February 05, 2002 5:58 PM
> Subject: [CR](no subject)
> > Classic bicycle enthusiasts:
> > Recently someone mentioned an Ideale 90-IR (aluminum railed saddle)
> > mounted on a Campy NR 2-bolt seatpost. Although for many years I have
> > known of the conversion parts that make this possible, I have never seen
> > them at a LBS. I would now, if it's not too late, like to purchase at
> > least one set of these parts (I have 3 of these saddles so more sets of
> > parts would be possible). Can anyone out there tell me where I can find
> > these parts? I thought they were made by someone like Joe Breeze, but I
> > don't remember.
> > "Bicycle Mark" Perkins
> > Fresno Cycling Club - Historian
> > Fresno, California, U.S.A.