BTS Turret Repair Rooms
Introduction
Workstation
Table
Create a prop_static and set its world model to models/props_bts/bts_table_static.mdl. Next, you can place some tools on top of it by creating two prop_physics entities with the world models models/props_c17/tools_wrench01a.mdl and models/props_c17/tools_pliers01a.mdl. While the official game didn't do this, I like to also put a tool organizing box on these tables as well, since I think it fits there very nicely. This is a physics prop with the world model models/props_lab/partsbin01.mdl. You can also put a radio on it if you want.
Turrets Under Construction
The ones you see pictured are simply prop_static entities with the world model models/props_bts/bts_turret.mdl. You can also put fully built, but malfunctioning turrets in the area. Create an npc_portal_turret_floor, and go to the "flags" tab. You can make it citizen modified (friendly), out of bullets, or just completely inactive.