What is the correct material to use..

I'm in the process of restoring some original Macs (a 128 and 512) with a friend and we have come across an issue with a floppy drive that is strictly mechanical, and am wondering what others have done. On the original 400K floppies there is a pin on the side that moves up and down as the floppy goes in, and is ejected which in some sense locks the floppy in either position. On one of these drives, the pivot point where this pin connects to the rest of the mechanism isn't as "free" as it should be, and initially caused the drive to be either stuck in the open or closed position. We've cleaned around the pin (Q-tips and isopropyl alcohol) and then lubricated it with some WD-40 (using Q-tip as well) as a start. This approach did free it up enough that it moves from "open" without the floppy, but when the motor goes to eject it, the mechanism is still a bit slow to move (which prevents the disk from ejecting by motor alone). Using the good ol' paper-clip shows that that mechanism works fine, though is just a little slow... which tells us that it's still not as free as it should be. We're trying to figure what type of lubricant would have been on this before (or what would be the proper modern replacement) Any thoughts? Thanks. Earl