You do not have to be concerned that there are eight terminals on the switch. As you can see, they are joined together in pairs, so there are only four different terminals - your first photograph shows "2" and "3" are joined together, "4" and "5" are joined together, "6" and "7" are joined together; are "1" and "8" also joined together?
The problem you have is the switch is not original, original switches had "1", "2", "3" and "4" marked on them, as you can see on the wiring diagram. Can you post pictures of the other side of the switch - where the key fits - with the key half-way out of the slot, so I can see how you have fitted the switch? Then I will look at the switch I have and tell you which terminal is which number on the wiring diagram. Then you will be able to attach the wires to the correct terminals by the colours of the insulation.