There are several methods for cleaning chrome, , surprisingly aluminum foil works great. Small pieces add a bit of water and rub the liquid as it turns /brown/gray/black; cleans and fills tiny holes too. . Brass brush is preferred by many which is a bit better for getting around the spoke nuts. and solvents of different chemicals. brass and aluminum, or Oleic acid are my preferred, albeit that acid trick requires more work than the book's cover indicates. And I don't care for most solvents b/c in short term can look nice but long term it's possible for its chemicals to remain in tiny areas, then come back to haunt you. Do not use steel wool, sand paper or any other metal brush type, they will scratch it and the average person may not see it but we WILL. .
As for your paint, only lightly on your decals and especially, most especially! your fender Guard, it's screen painted and the white can just wipe right off. Those fenders are not actually Schwinn, they're add on's by dealers and cheap enough buy to replace. Yet the rust doesn't look very heavy so, prob clean just fine. Or even better; pick up a cheep 1995+ Schwinn cruiser with chrome fenders and front duck tail, for practically nothing on C/L. rob some parts for other bikes and trash the rest. [grin]. You got generic fenders as it is, so, who cares? How does me know? B/C Schwinn fenders would have a duck tail and , on the brackets, the flat area running under and attaching to it, that flat area will be much closer to the side of fender; approximately 3/8" to 1/8" flat area showing. .Albeit there is this possibility in replacing cheapo china generic fenders to newer cheapo china Schwinn fenders; The purest may want those b/c most know the dealer did that. Check this site's maintenance section for more cleaning/detailing aides.
You best item on the whole bike is that chain guard, nice clean and strong screen printed white paint remains
guard it (see how I did that?) wit you life.
B/C everything else can be bought in ebay.
other than the top bar Schwinn decals, elbow grease and determination to cash in highest value, your bike will clean up berry nicely. Yet as is because that chain guard's white paint is so nice, there's a good chance a buyer who knows to clean would be happy to get for good price minus 50-100 bucks to clean it up him/her self.
That wouldn't be me b/c, I'm holding on too the delusion that, some dope will dump one on C/L, near me, fer nutin.