Not really RC, this. Still fun and very mechanical. It’s a bit like working on old servos ...

After restoring my cousins little Märklin locomotive with good success another FOUR landed on my desk.

There is not much to these little items - knocking out the pins holding the wheels gears and then the usual stuff like cleaning gears (filing the teeth, rubbing etc to get them perfectly smooth) polishing the commutator, soldering up the cables etc.

The electromechanical direction switch relay is probably the most intricate part.
I used some LiPO batteries in series to set it up....

The old track built in 1958 still works fine. Looking forward to locomotion in 2019.