A local developer has bought a former firehouse and plans to turn it into a hub for multiple businesses, a project he has pursued for the past nine years.Mark Callazzo and his RMS Capital LLC bought the former Fire Station 7 at 535 Atlantic Avenue last week, and have filed an application with the Casino Reinvestment Development Authority to restore it and prepare the inside for use by yet-to-be signed tenants.The $3 million project will be heard by the state agency in its capacity as land use regulators for the city’s Tourism District on Jan. 15, Callazzo said.