Ask and you shall recieve! (Flip Top Gas cap Adapter)

Hole pattern is typically not an issue. Though the "Three hole" pattern I have gathered is backwards from cap to filler neck. This would just require a few new holes drilled in the cap. :)
I would rather drill holes in the cap than the car, for the sake of being able to remove it all for re-sale or originality.

Thats my take. :)