Jerry Moos wrote:
"It seems the most fancied models are those which had alloy frames or were available with such."
I just received an original copy of the 1976 Palo Alto Bicycle Shop catalog and found this quite interesting (See attached link to catalog scan). It appears that at the time Ideale may not have made a differentiation in the Wholesale pricing of the Steel or Alloy railed Model 90 saddle. In a conversation with a friend, he commented that maybe that's why Ideale went out of business. Not charging a premium for the lighter Alloy version.
Alloy railed Saddles date back to the earliest years of Ideale FT. Only in recent Decades have they commanded premium prices due to the expanding Collector Market. I do suspect they are rarer because they could only be used with the common Seat Pin of the time and appropriate clamp, where the steel rails were useable with a much wider variety of Seat Posts.
Jay Dubiel
Halifax, Virginia USA