Chances are the bearings and chain were cleaned up and regressed, not replaced. The tires don’t look like new ones to me. I wouldn’t sweat it. The value on this type of bike isn’t affected much by stuff like that. You get into high dollar bikes that people pay big bucks for because of originality, people start to get a little more picky about stuff like that. But this bike is a cool, worn rider. Make an offer on it that you are comfortable with. If you get it for that, ride the heck out of it and enjoy it. If you don’t, keep looking. They pop up often enough. This happens to be my very favorite basic Schwinn platform. I’ve bought no less than 12-15 in the last year right off of this site. But with that said, a basically all original one that is still in presentable condition and is available for a reasonable price doesn’t come up every day. Go for it!