End of the bubble...

...well, almost. By now I figured that any air inside the compass would have worked it's way to the top. The bubble grew the first day, but since then it's been the same size. This evening I put the compass back on the bench, opened the filler hole, leveled the hole to get the bubble as close to the hole as possible, and injected a small amount of oil to top it off. I ever so carefully put the filler plug back in place, and returned the compass to it's upright position. There is still a really small bubble, about the size of a pencil point. I'd like to get it out, but it might be too much trouble.