Tool to remove ralley gas cap???

Anyone know where I can get the tool to remove the ralley gas cap?

1968 Plymouth Barracuda

I thought it would be a regular old Phillips hear screw, but there are 3 fasteners and they have 3 little indentations like for a special tool to remove them.....

99.9% ready to send to paint and I can't get the gas cap off....LOL







Jeff