The Unknown Tune is
Till We Meet Again
Words Richard B Egan Music Richard Whiting 1918
http://www.firstworldwar.com/audio/tillwemeetagain.htm
My mother and Grandpa used to play this on piano in the forties. As a slow waltz. It was very popular.
I have heard but cannot name your #3 On the tip of my brain. I am pretty sure Louis Armstrong played it in Dixieland style. Anyone else?