I cannot for the life of me find the image I saved from one of the unit sites but it was pretty good. I have seen these in many variations - some with no lightening bolts, some with two, some with four. It was suggested somewhere that the bolts were added as combat experience accumulated but I could never substantiate that much less what additional bolts would have meant.
Wayne flew with the Screaming Red Ass squadron and his was painted directly on his Perry. It had four lightening bolts if I recall. Too bad it was so faded. He doesn't know why there were variations.
One I did in enamel:
Looking forward to seeing what you come up with,
Dave