All well and fine but incomplete.
In order to get the chest key you need 4 broken keys... and here by my count it list only 3. So what comes after this section:
K20) Estero Park Kayak Landing > go up and right in the same area > chest key reached with a whip
C20) Lighthouse Lighthouse > Albert's room > South > West > new area
K--) Lighthouse Spanish Fort > West after using gunpowder on canon (Crypt Key)(access to Crypt in Cemetary)
K..) Crypt East part > low right corner (Broken Key 7) ??
Where do I get broken key number 8 in order to craft the chest key?