I have a Sept 1974 Yellow Tandem Twinn Delux.

Good news is they are nearly indestructable. Bad news is they are heavy,ours is 66 lbs with nary a water bottle or accessory installed.

Be sure you pull every bearing in the thing, and clean and lube them. The loose ball bearings weren't that great to start with, and I'm sure you have some rust and pitting somewhere by now.

Also make sure to find some tires that fit the Schwinn rims.

Have fun and keep us posted.

Ramius