If the frame is black, (i'd recommend this for most colors but black in particular), One Shot Lettering Enamel. Look around and you can even find that in a half pint I believe. Self Leveling, high gloss, excellent adhesion, no sanding before or after. Just fill the chip hole with it facing up, (defect level), wait overnight, (12hrs. min.), and done. May be off a tone, but the repair is easy and neat. Use a quality brush, and a light pre-application of rust preventative primer if there appears to be rust in the chipped area. The lead in the paint, (yep Still Lead Based), would likely take care of the corrosion anyway. Easy repair with great results, and no surrounding areas to blend. It should flow to the edge of the chip and stop like filling a swimming pool.