Throughout the 1970s and 1980s Scalextric cars used little metal pins or rivets to connect the pick-up braids to the wires that go to the motor. The wire passes through these hollow pins and the conductors are bent back on the outside of the pin. Originally the pick-up pins were brass in colour and had a diameter of 1.95mm. Later, during the 1990s, the pins were changed to a silver colour and the diameter was changed to 1.75mm.
The two pins are very similar to look at apart from the colour.
However, the modern service part for the 1.75mm pin is now brass too.
So it’s now impossible to look at a pin and decide its diameter. The
only way to tell them apart is to measure the diameter with a micrometer
or try them in the guide moulding.
The only really certain way to ensure a match is to replace the original guide and pins together as a complete guide assembly.
Another great insight from Scalextric Car Restorations