This is a Erie 77 I had a couple years ago.
I used light hits with a hammer or hard metal surface and also light flaking/picking it away after cracking the paint on top of the decals,,, and a lot of time.
I would not suggest using paint thinner or some chemical for fear of wiping the graphic out too.
Good Luck and have fun!
LOOKING-4:WELDING SIGNS,Charter/Finance/PulOil/Trulite/TruTest-Oils,True's gas CORALINE/RAINBOW, Gardner 70 items of Yakima wa., Wa/Or/Id Chief items