On a chilly afternoon in February, Logan McGrath and Mack Fritz were preparing to shoot a video advertising the green Austrian army fatigue shirts they were selling on Americana Pipedream Apparel, the online military surplus store Mr. McGrath started out of his parents’ basement in Appleton, Wis., three years ago.
After outgrowing their last two locations and grabbing the attention of customers like the singer Post Malone, they had recently settled into a new venue: a onetime furniture showroom that was repurposed as a 24,000-square-foot warehouse. The large space was already filling up. Afghan war rugs were piled up in one corner. Tall laundry bins held hundreds of American military canteens and current-issue British camouflage uniforms and equipment. Cartons of energy drinks were stacked by the fridge.
More than a dozen employees, mostly in their early 20s and friends of Mr. McGrath’s from high school, crisscrossed the space on scooters, Segways and skateboards. They collected Greek camouflage jackets, West German military patches and packages of vanilla poundcakes from American military rations, assembling them for orders. In the back of the warehouse, they sorted through pallets of surplus that had arrived from as far as Indonesia and Pakistan, including about 1,500 grayish-green Austrian KAZ-75 field shirts.
Nearby Mr. McGrath and Mr. Fritz, both 21, worked on a video to market the shirts on their popular Instagram page. The two young men gathered around a folding table in Mr. Fritz’s office, the furniture business’s old paint studio, and scrolled through the script they were editing.
“Have you ever seen Austrian drip go this hard?” Mr. Fritz, wearing an orange down jacket, proposed.
