"Bicycle Mark" here.
On the question about the difference between the Peugeot UO8 and AO8, I believe I can help a bit since I once worked in a bike shop where I assembled these bikes, and I own a mid- to late-'70's UO8.
The AO8 was the bottom of the line in the early '70's (not sure before then), and came with Normandy hubs (I believe small flange), with solid axles and rear hex nuts & front wing nuts, and had no chrome on the stays or forks.
The UO8 was the next model up from the AO8, and came with Normandy LF, QR hubs, and had chrome on the lower half of the forks, and I believe some years had chrome on the dropout half of the stays.
There may also have been differences in frame materials, color availability differences, and one may have come with an aluminum pump while the other didn't, but they both had the same rims, derailleurs, brakes, cranks, etc.
As for the Ideale saddles, I know more about their leather saddles than these padded, leather covered, plastic shell type saddles. However, Terry Shaw of "Shaw's Lightweight Cycles" in Santa Clara, Calif. would be able to answer your question because not only did he sell them, I believe he rode them.
Incidentally, I also own a 10-spd., and a 15 spd. late '50's or maybe '60's?? Peugeots with pre-plastic, steel Simplex rear derailleurs, cottered steel cranks, and fancy Nervex lugs, but I know very little about them and welcome any info. anyone out there can provide.