I like the trading thingy more. I suspected, from the background given about the Lakefolk being good smiths, that the town had at least one, in which Kurin could be teaching the humans how to do thing correctly.
There are 3 cities involved (see the map in
this post):
Erebor, aka The Lonely Mountain, the Dwarven city/kingdom
Dale, the human city at the foot of the mountain
Esgaroth, aka Lake-Town, south of Dale on the Long Lake
Bardings (followers of King Bard of Dale) live in both Dale and Esgaroth, but Dale is the city that's learning smithcraft from the Dwarves. Esgaroth is smaller and more rustic, but as it's on a crossroads for water traffic it's becoming a hub of trade. (It's more convenient for men of Dale, Dwarves of Erebor, and outsiders to all bring goods to Lake-town to trade rather than forcing caravans from outside to travel further north upstream to Dale and the Lonely Mountain.)
The history (from The Hobbit): in olden times, the the Lonely Mountain was a mighty dwarfhold and Dale was the capital of a prosperous human kingdom spread out throughout the wide fertile lands at its foot. But when the dragon Smaug came out of the north and drove the Dwarves out of the mountain, he also ravaged Dale, burning its fields and turning the entire surrounding countryside into a wasteland called the Desolation of Smaug. The men of Dale who survived fled south to the Long Lake and founded Lake-town, while the Dwarves who survived fled east to the Iron Hills.
Many years later Smaug attacked Lake-town and, although he burned most of it, he was slain by Bard the Bowman, a descendant of the last King of Dale. Dwarves of the Iron Hills returned to rebuild the Lonely Mountain, led by Dain Ironfoot who became its King. Bard was proclaimed the new King of the humans, and most of the surviving men of Lake-town followed him north to rebuild Dale. But some remained to rebuild Lake-town, and they also acknowledge him as King.