The Peleton is by far the better frame, both in terms of materials and construction. The Seville was CCM's top model for 1979-1981, but the company was on it's last legs and struggling. The adult, 10 speed line was whittled down to 3 models, with the Seville selling for under $300 CDN. While it did have 600EX brakes and derailleurs, these appear to have been customer bait, as the cranks were Tourney and the other components are unamed in the specs. Even the tubing material is not listed, which is not a good sign. The previous top model had used Reynolds 531, but even it was only plain gauge, so the Seville is almost certainly lesser. The posted seat post diameter (26.4mm) indicates plain gauge CrMo, but it is almost certainly only the main triangle and possibly only the seat tube.

While there is much to be said for a properly fitting frame, I suspect you will find the ride quality vastly different from the Peleton and the "fast" ride you are looking for. The Seville is more sports/touring geometry with relatively slack angles, long wheelbase and lots of rake. I suspect you are going to find it heavy, unrepsonsive and slow, relative to the Peleton.