The controller at Gloucester sitting in front of the ATM in the VCR is not necessarily a Radar controller. An Approach procedural function is usually supplied from that position, using the ATM as an aid to provide traffic info etc.
Unidentified traffic with conflictions may be advised "Traffic BELIEVED to be in your 2 oclock range 4 miles crossing right/left etc etc"
It can be legally used by a procedurally or tower rated controller
so long as a radar service is not provided.
Gloucester also has some fine radar controllers. They use the same kit for separation, sequencing and I beleive now for 2 mile SRAs. The main radar screens downstairs are used for half mile SRAs.
However, since that program you talk about (A Plane is Born?) was filmed before the recent radar upgrade, this may be out of date info, as I haven't worked there for 5 years.
Perhaps Matspart3 could divulge some up to date info.