The third image (Fig C) down showing the two joined curves with the yellow wire, I think that if you separate those two curves, you might find that the yellow wire is actually simply pushed between the two silver 'tongues' of the center rail and will come out.
The center rail is normally a Red wire, and the outer rails which are joined to the metal track-bed should be a Brown wire. Here's a original feeder track showing this... the wire colours match the connectors on the controller, which as noted, is quite old. Using plugs of the same colour from the small tin keeps it all simple.
The controller markings are...
'O' (Brown) = Ground / Earth if you like, (is also easy to remember as "Outer" (Rails)
'B' (Red) = "Bahn" (loosely German for railway current) - A real easy way to remember this is being the output controlled by the RED knob.
'L' (Yellow) = Lights (Licht) - this is a constant voltage output, no control.
Novices often mistakenly think 'B' = Brown but how or why they then equate O to red is anyone's guess.
Second image (Fig. B), that controller is normally for a Slotcar, although it 'could' be used with the train I would disregard it for now and just concentrate on getting an oval of track working well, then you have a basis to build from.
Figure D is a control panel for connected accessories - leave aside for now
Figure E is a signal, ie a traffic light for trains basically - leave aside
Figure F is assorted items, and what's shown indicates there must be a bit more not shown.
For example, the buffer stop would be at the end of a siding, and for a siding you need turnouts (switch / points), so I'd expect to see at least one of those.
It's all relatively simple, start with the basics and it should start to make sense. This all assumes that the Loco itself works, no missing parts like the pickup shoe underneath.
So at the very least you need a few sections of track joined together, wires to the controller, and confirm if the Loco actually runs. I'm just trying to get you up and running with what you have to confirm you have something worthwhile before spending too much money only to find other problems.
A final note re the Blue controller, jabez is correct that it's one of the older types, however it's not one that is usually found to have perished wiring. It looks very much like a PVC mains cord rather than rubber but if in any doubt, have a sparky or appliance service-person look it over.
Cheers
