I would like to present one of them in more detail here.
It is the smallest fixture ever built in the GDR for mercury vapour lamps.
This fixture was put into production around the beginning of the seventies. It is a housing made of cast aluminium with a small steel cover plate for the ballast compartment.
The fixing spigot for mounting on the pole bracket is a separate component made of cast aluminium and is mounted on the housing with 3 steel screws. The complete fixture was clamped to the mast bracket with just one screw.
The opinions of lighting technology experts in the GDR on this fixture were unanimous: completely unsuitable in terms of lighting technology.
And the experts were right. The housing in the area of the lamp was only painted with a colour similar to ivory. There was no reflector. So you can already speak of a ‘sparkler’.
This fixture was mainly only used in small villages and in areas where there were no major lighting requirements.
This fixture was manufactured by the company ‘PGH Leuchtenbau Staßfurt’ and has the designation ‘R70.1’. In the first years of production, this fixture was still available with a ballast for 80W and 125W mercury vapour lamps,
which could be optionally reconnected at the terminal. The last models only had a ballast for the 125W mercury vapour lamp. Colloquially, this fixture was called the ‘Latschen’ in the GDR, a German term for an old shoe.
A few pictures of different versions of this lamp supplement the text:

This photo shows two uninstalled fixtures with the older bakelite terminal and the ballast for 80W and 125W mercury vapour lamp,
optionally clampable and the later version only for 125W mercury vapour lamp with the newer form of the terminal.

This photo shows a used fixture in detail with the old bakelite connection terminal and the four connections for the phase (L), tapping for 80W, tapping for 125W and the protective conductor (PE).
You can also see the problem with the corrosion of the aluminium.

This photo shows two used fixtures side by side, both fitted with a 125W mercury vapour lamp.

It can be added to this photo that the connections are somewhat special in terms of electrical engineering.
In the GDR, so-called ‘zeroing’ was permitted until the ‘reunification’ in 1989. In concrete terms, this means that the phase goes via the black cable and the neutral conductor and the protective conductor have a common cable (PE).
In this case, the connecting cable also has only two cores: black (L) and green-yellow (PE).
In the FRG, ‘zeroing’ had already been prohibited for new installations since 1973.