The headquarters station in the episode was the actual SFD HQ (station 10), and has an indoor swimming pool on the 2nd floor with a large "10" tiled on the bottom. The 100+ year old station is now a fire apparatus museum, and is open to the public. The new FD HQ is located three blocks to the east.
The numbers stenciled on the side of the firefighters helmets accurately depict actual SFD unit designations from that era.
Shepard Ambulance was an actual Seattle ambulance company, before being purchased by AMR in the mid '90s