As mentioned in my "me and my layout " topic, older Märklin pantographs are a bit wobbly and when using the overhead system for real I've had problem with them, a.) not staying horizontal an b.) moving sideways.

I've looked at the possible improvement by inserting a rivet (spare part from Sommerfeldt) into the upper arm and so it came to take the pin out of it by cutting it at the end with a pair of pliers.
the next task was to increase the hole to 1.5mm and the same with the slider. the rivet is 5.3mm long and it was a bit too short to come out the other end so a shaved off a bit of the upper arm t - junction on both sides.

here are the tools I used: