Originally Posted by rxda90

Same Ashtabula crankset as the Varsinentals. The rear derailer is GT100, and the front is GT750 (I think that's what it says).

(From http://www.geocities.com/sldatabook/serial.html)
Bicycles from Japan will have serial numbers located on the left, rear axle hanger, on the bottom bracket shell or on the lower section of the headlug. The number will have a production month letter in either the first or second position and a production year number in the other (first or second) position. Examples: J677123 = September, 1976.

(And from Panasonic Bicycles at Yellow Jersey)
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 Traveler. It was priced between the Varsity and the Continental but with a lugged frame and Shimano equipment.