Thank you for the interesting presentation. First time I have noticed the 'scale' at the bottom of the first page. The scale is interesting because these old explorers were 'pretty good' in a wide range of subjects.
Some things stand out ref the coffer in the 3rd pyramid.
1. Number of 'star' figures depicted indicate 12 on side and 6 on end of coffer x 2 = 36 around the coffer.
2. Looking at the measures of the length width and height (without including the lid which is in fact in pieces on the floor somewhere). The measures may be a little rough but clear.
They are length of outside of coffer 8 imp feet
Breadth 3 imp feet.
Height 3 imp feet without lid.
Volume of outside of coffer without lid 72 cubic imp feet.
Volume of inside of coffer 24 cubic imp feet.
width 2 imp feet
length 6 imp feet
inside height 2 imp feet
The inside volume of the coffer is 1/3 that of the outside of the coffer(WITHOUT THE LID)..