Used stamps exchanges.

I am still fairly new to this and trying to work out what sendings deserve which ratings. I don't understand why this one received 4 stars only ? Seems the club rules were complied with and, unless stamps were damaged, 5 stars should have been allocated ?

here is the message from KLM04889 .... Received today old Canada sorry.
Greetings René .... I have a hard time understanding, there are no old Canadian stamps

This is worth 6 star Laurent.

Rate KLM with same rating

KLM should change his/her rating as it seems totally unjustified!