FALL RIVER — Did you know they make high-end men’s trousers in Fall River’s Flint neighborhood? The Hertling manufacturing company, besides making its own line of pants and shorts, manufactures private label trousers for such men’s clothing lines as Paul Stewart, J. Press and Epaulet. And although the company has been around since 1925, they’ve been in the Spindle City for barely two months. Majority owner Justin Christensen relocated Hertling in March from the Greenpoint section of Brooklyn to the third floor of the Tower Mill converted mill building on Quarry Street. “We have twice as much space and air conditioning and pay 80 percent less in rent,” he said.