I'm guessing the scan provided is a misprinted copy. The map shown for Mine level 3, is actually mine level 1 again.
proper version here. http://www.mocagh.org/ssi/ssb-hintbook.pdf

Yes I download all documents from Mocagh again . Their quality are awesome . I wondering why all documents aren't from Mocagh.org ?

Yup looks like they got the misprinted one if that's the case.

There were definitely 2 printings of the clue book as back in my youth I had owned 2 copies of it ... the first came with a yellow insert sheet with Mine Level 3 on it while the actual book had Mine Level 1 on both pages; later on I ended up buying the clue book again (I recall the first copy getting mangled somehow) and Mine Level 3 duly appeared on the right page ...