Carson, the contacts are the switch I mentioned previously that cut off the cartridge output while cycling so as to not transmit mechanical noise to the preamp/receiver. I may have mis-stated it's functioning as I was pulling out a long-dormant memory. I since got into my 50H to more accurately guide you & anyone else.
I believe it shorts pickup leads to chassis ground, you can see it in action while manually turning the large gear, which is the cam that moves everything. At rest, the contacts are open, while cycling, a raised part on cam gear closes the contacts. If you hear any noises in your speakers while tt is cycling, these may need cleaning. Not to worry about blackness, as silver plating gets that way.
As far as grease goes, elac used good schmutz (lube) that lasts a looong time. If it's dry & crumbly, clean out & relube with lithium grease, or even gun lube. If grease is still"greasy", I'd skip cleaning it out. Shouldn't need to deal with bearing pack on platter spindle, it's lubed for the long haul. Put a drop of oil on the idler wheel axle, do not get any on the rubber! Clean up friction surface & inside rim of platter with 91%isopropyl alcohol.
For spring foam r&r, I just did my 50H with cones cut from foam egg crating, see pic.