It is a lunfardismo. I added a source to the definitions already given. In the 1930's the snobbish people in Buenos Aires was fashion using a sack ( 41 jacket; fabric pictures with pitucones ( patches ) at the elbows, although it was clear that the sleeves weren't broken. By this feature began to call them " pitucos " ( was prissy people, usually of high class, with modal affected ) and the word was still used after disappearing patched elbows fashion.
swanky it is incorrectly written and it should be written as"manners." being its meaning:
Correct person, in his manners to eat, behave, and way of dressing. Demure, discreet. With what is seen and where they are, these people are differentiated. By your way of being. Who has manners together who are not, branded Pitucos no will in hand, having good economic status, race, color of skin, whether they are ordinary. What is said here. Broken got people
