UnScramble this Word: i r e i b t l t?

Questions

50s: This European principality gained a princess in 1956?

50s: This flop car was introduced in the 50's?

60s: 1964 release was the most successful Disney film to date?

60s: First nation ever to resign from the united nations?

60s: This bridge, the largest suspension bridge in the US, was finished in 1964?