At Leading Shoe Rebuilders Everywhere

This ad for Biltrite shoe soles - "BEST by any test!" - has seen better days. It dates to 1947, which we know because it is located in a St. Louis Public Service bus that was retired that year and benignly neglected until acquired by IRM in 2015. I'm actually not sure exactly what it says, other than the dark-colored lettering and "America's Standard of Quality" across the bottom. "BILTRITE will not something / something heels and soles" - any ideas? Just make sure you see a leading shoe rebuilder and not one of those knock-off shoe rebuilders.