Great job by the way. You pic of the 'dining area' - what is on the center of the floor?? My boler had a bolt sticking out in the center. I could not figure out a purpose for it so I cut it off as I could not get to it underneath. Was this bad?????
Well that bolt was used to hold up the table leg, so it was kind of important.
But it should be an easy fix. Simply drill the old one out ( whats ever left of it ) and replace it with another from the bottom up.
You could fashion some type of wood peg that would be just a bit smaller than the hollow leg. Screw the peg to the floor and then the table leg would simply slide over the peg. A piece of round dowling would work fine. Cut a piece about 3/4 - 1 inch in length. Drill a whole down the centre of it and then screw it to the floor.