Dont know what it is about the old vw paints. They chalk up like yours and
mine did.I think that is good.Dupont polishing compound will remove the
oxide and provide a shine that you may like better than a new paint job.It
comes in a round , flat can , like most waxes. Has green lettering.Easy to
find.You must protect this new shine with a wax coating ,or it will
reoxidize,back to whence it came, in about 6 weeks.