I went so far in this looking at how many skull bones are there and what could be the top ribs! and BTW there are 7 main ribs in human body! which made it possible to be a clue ;p then tried to figure out what could the circle and dots mean!! before realizing that I can get the bold easily but again it took some time to figure out the light ones..
I was thinking that the bold number is the number of letters in the words combined. This works for all of them. The lite number is the number of repeating letters between the two words. This works for all except the first one. I assumed that was another error similar to the one on page 42. But then I can't get the solution. A nudge would be greatly appreciated.