The issue of the correct rear der and brakes on the early '70s Paramounts is a matter of no little interest. Which one is correct. Here is a note I 'borrowed' from the Yellow Jersey site:
" Tellingly, Schwinn's first outsourced bicycles were built by Panasonic, sold as "World" bicycles in 1972. Panasonic was the only vendor to meet Schwinn's rigid standards when they could afford to be picky. Still and all, the Panasonic bikes met initial dealer resistance as "imports" and were not included in the Schwinn consumer catalog. Schwinn's standard model from Panasonic was the World Traveller. It was priced between the Varsity and the Continental but with a lugged frame and Shimano equipment. Schwinn also marketed a top shelf touring model from Panasonic, the World Voyager, lugged with butted Tange tube, lots of chrome, forged ends and Shimano's excellent Crane changers with Suntour bar-end shifters. This was serious competition to the Paramount series at half the price. Mechanics knew the Shimano gear was clearly superior to Campagnolo's Gran Turismo on the P15 Paramount. By 1974 the Voyager was quietly dropped, the Shimano Crane derailleur appeared on the new Paramount Touring, and Schwinn made a large commitment to Panasonic-built LeTours which would become Schwinn's second-most-popular model through the seventies."
And here is an ad from American Cyclery in SF for a "1972 Schwinn Paramount P-13":
"22" touring bike. All chrome frame with Reynolds 531 tubes and Nervex curly lugs. 15-speed with Campagnolo Record triple crank, Campy bar-con shifters, Shimano Crane wide ratio rear derailleur, 27" alloy touring rims, Weinmann brakes, and Cinelli Unicanitor saddle. This bike has been ridden less than 20 miles and is in great shape except the tires are in need of changing."
Okay, clearly not anywhere near an original bike, but pulling the Campy off the rear, and going with the Schwinn-badged Crane was indeed a 'period mod', as was changing over to the Campy sidepulls, an option on at least the 1974 P-15 from the catalog that you can access on line.
In some cases, the earlier Paramounts, such as mine, left the shop this way. I have most of the original notes on my bike, and the change to the Campy sidepulls and the Crane were on this 1973 bike when it left the dealership in 1974, 'upgraded' to the better brakes and better rear mech.
So, while it seems that quite a few 'touring' Paramounts, of whatever designation, have had the "inferior" (it's okay, I am still a Campy buff, but fact is fact) replaced by a Crane (in my bike's case, a Schwinn-badged Crane that was current the year this 73 was sold in 74), the Campy sidepulls that were a common upgrade are now being replaced by the then-less desirable centerpulls. Isn't the quest to be 100% authentic great :-)
Dave Novoselsky, Chicago Illinois