This ex Holland Signal precision resistance box had broken 10k resistors. This was caused by corrosion of the copperwire that connected to the top of the resistor. The strange thing was that it only happened to the top wires.
It is a precision decade. The zero ohm resistance is very low. They use two types of metal for the conductors from resistors to output.
The zero resistance 0,0138 ohm.
Under the front panel you find the big scaled knobs.
Under those disks we find part of the magic. Heavy duty low EMF, low resistance switches.
If we look at the next picture you see the switch is made of several parts. All bolted to the metal plate.
You do not want to know the price of this resistors. The 0.1 ohm is nothing more as a loop of manganin wire.
They are beautiful made from manganin wire wound on ceramic pipes. Look at the ropes that fixate the ends.
Some of the 10k resistors are now just outside the specs but as l;ong as you knowe it does not matter.