Old style phone connectors were pretty much like the connector block described above, with 2 main differences. The phone cord wasn't connected via screw terminals, it had spade connectors. And the cover screw had a seal sticker with this logo over it.

[Linked Image from members.aon.at]
(Of course without the Post.at text, that's recent www-frenzy nonsense. They even call their Postbus service Post.Bus).

There were four terminals inside, only two of which were used. IIRC they were A, B, E and W2. E was probably Earth (never saw that used) and an auxiliary bell would be connected to A and W2.
Party line phones used a huge relay box (about 20x20x10 cm) until they disappeared in the late 90ies or maybe even early 00s. Later there were several styles of modular jacks. The residential version was pretty much like a 4-pole version of a headphone jack only it got thinner towards the tip with each ring. About 1cm in diameter (first ring). Usually only one socket, if there were more they were wired in some master-and slave setup that prevented from overhearing any conversations. Commercial locations used a 10 or 12-pin rectangular plug (angle plug with all the pins sticking out). Later the so-called TSS plug was introduced. TSS stands for "Telefon-Steck-System", i.e. phone plug system.

[Linked Image from holzinger.cc]

and the matching socket as it is usually installed by the Telekom, 3rd party sockets look different.
[Linked Image from holzinger.cc]