I've taken apart a road bike from the 70s with a (french) ball bearing bottom bracket. Looking inside I found (what I thought to be) absurd amounts of grease in the tubes coming into the bottom bracket. I'm a bike work beginner and intuitively I would've thought that's excess grease pushed into the tubes, but the sheer amount made me wonder whether it's there intentionally - maybe to seal off the tubes/bottom bracket?
Also haven't found anything on it yet on Sheldon Brown's website, but that might just be my fault.
Thank you for your help.