Along the lines of your first suggestion, I've scraped paint off raised emblems with my fingernails. No need to risk dripping thinner or whatever where it isn't wanted.

Spray your button at 90 degree angle so as not to get paint on the sides of the stripes or letters.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)