The top one is indeed a water drain.

I find that with my K-70, I have to top off the lubricant a couple days after filling the gear case — after it sits for a while and finds its way through all the nooks and crannies.

When I was young, my father used steam locomotive grease, which was so thick he had to remove the front cone and pack it in from there. I imagine my grandfather did that too, which is why so many of my grandmother’s wood spoons are missing 🙂