The sign "DON'T BE HALF SAFE" refers to Arrid deodorant. During the 1940s and 1950s, its famous slogan was "Don't be half-safe-use Arrid to be sure", which gave rise to "Half-Safe," the name of the amphibious vehicle which Ben Carlin used to circumnavigate the world.
The bulldog utters what would become future cast mate Tweety's famous line, I thought I saw a puddy tat.