The other question I have about lubrication is the frequency. The older machines like the Singer 221 have oiling intervals of daily and weekly translated to 8 Hr for the head and 40-50 hrs for the bottom. I'd need to watch the video to pin it down. Oiling is a user operation so there are instructions in the use manuals if there is one on line. The other issue worth enforcing is that all one needs is a drop in the right place. Too much oil will result in getting it where you do not want it.
If one does not have a manual but has an older machine the Singer 221 manuals are all on line. I expect the bearing and oiling requirements are all about the same for the older machines is it is material driven. Pulling one of those manuals up would at least give a clue what to look for.