The Ethyl logo is fairly standard - even if it's the EGC version.

And I believe there's enough detail left to reproduce the decal.

You'd just need to figure out the outer background color and the color of the lettering.

The lettering looks like it matches the Sweney Sky Hawk . . .

Sky Hawk / Black Hawk?

I'd be interested in recreating it for you if you want.

Later . . .

Jim