An apartment development planned for a sprawling former industrial tract could bring approximately more than 400 new residences to the edge of the North Loop neighborhood in Central Austin, according to site plan documents currently in review with the city. The project by local real estate development firm Seco Ventures would raise two adjacent five-story apartment structures facing East Koenig Lane on a roughly seven-acre property located near the rail crossing at 403 East Koenig Lane, which until its closure . . .