If you're interested in finding when the bike was made, look on the headbadge and try and find four small numbers stamped on it. Many Schwinns have this assembly date code on them. The first three digits will represent the numerical day of the year,the last digit will represent the last number in the year. Example: 1567 would mean the bike was assembled at the factory on the 156th day of 1987, assuming it's an '80's bike, which your Prelude likely is.............If no date code is there, go to www.vintage-trek.com and look in the "component dates" section. You should be able to find the date codes stamped on your bike's components and match them with the codes listed on the site..............If you can determine what year the bike is, there's a good chance Scooper will have a catalog scan of that year's Prelude-