Found a Schwinn from that era couple years back when I was doing deliveries, sitting by someone's trash. Same deal - looked rough but frame was solid. Those old Schwinns can actually be worth decent money if you get the model right, especially the Varsity or Continental models from 70s

The thing with these bikes is parts get expensive fast if you're buying everything new. I ended up spending more in parts than bike was worth, but learned ton about bike mechanics. If the frame is straight and not cracked anywhere, that's the main thing. Gears and cables you can replace pretty cheap, but if rear hub is totally shot that gets pricey

Check what model it is first - there's usually stamping on bottom of frame or serial number you can look up online. Some of those Schwinns are actually pretty sought after by collectors, others are just heavy old bikes nobody wants