KM# 835 sweden seems to be wrong according to the "2007 Schön World Coins" Catalogue. There was never a 1961 mintage. it starts with 62. maybe check this. same for KM#368 norway. it says in catalogue 1908-1952.
KM#849 sweden maybe needs a separition into two (849 and 849a). Metal changes at 1981. There is a picture of the copperzinc coin at worldcoingallery to use. KM#826 and KM#852 also have metal changes over the years giving their KM# number to suffix "a".
that counts most definitely for many many coins in the database. maybe there should be a guideline that either tells to make a notice at the year section when metal changes or to seperate coin mintages in two (or more) independent entries for each metal. what do you say?