That one's a beauty. Did you do anything with the rust spot? It doesn't look quite right for pin rash. At least it isn't right on top the decals. The machine looks great other than that one spot.
IIRC one of the members here (Glenn maybe?) made a paint by mixing shellac and black pigment to fill in areas like that.
Other black paints built up to fill it in would probably work too. A little shellac over the top would help everything blend in.
Rodney