Files involved in unlocks and game progress
I moved from one PC to another, where I was playing the game at previously. I had many of the unlocks, and played quite a bit. Then I moved to a new machine and none of it was there after installing the game through steam. They don't sync the game progress or preferences up with the steam cloud like in TF2 or many other steam purchased games.
How I got my unlocks/progress back: copied both the pnati_save.save and the prefs.prop file from the "/Users/MyUserName/My Documents/Telltale Games/Poker Night at the Inventory/" directory to the same directory on the PC that I am now playing on. When I tried copying JUST the pnati_save.save, something didn't work right, and none of the progress was recalled.
I recommend to anyone playing this game, to back those 2 files up regularly if you care about your progress or in-game unlocks.