Clean the area with something that won’t scratch it,
something that will make it shine, will be easier then to see if it’s a crack or scratch.
I don’t know the name of them, but we get green nylon pads, 1/8 thick by 2x3 “ in shape,
they clean as well as steel wool but leave no scratch marks, that’s what I would use to
see whether or not you have a crack or a scratch that removed the paint.
If you try to clean up that area, make sure to tape up the frame well so you won’t
dull or damage any other paint, cut some thin but dense cardboard to wrap the
tubes and use a little tape to keep it in place.