I can confirm that Galloway sleeves are dropped by the boss at the second level of Delta 7. I was fortunate enough to receive them. Where do all of the other items drop? Miner for the mine sweepers.

Still, I wonder, which set is superior overall? The platinum shop stuff or Galloway? I'm leaning in favour of Galloway due to the dex - that's 36 extra dex (helm, front plate, back black, sleeves, legs, and gun).