I can assure you I am significantly older than MULTIGRADE II, but thankfully not MULTIGRADE I
( Circa 1940 ).

Whilst the 'matching' of the grade speeds with MULTIGRADE filters has changed the much bigger issue is with the age of 'these' MGII filters themselves, they FADE, slowy, but they FADE and the more they are used the more they degrade by 'WFS' ( Wet finger syndrome ) and 'LOTBS' ( left on the bench syndrome, instead of being put back in the box provided . We want everyone to get the maximum use out of every ILFORD Photo product....and 5 years minimum with care should be easily achievable.... but you can use them for longer, whilst they may not fade at exactly the same rate, as they fade you will move 'down grade' as opposed to 'up grade' so as long as you are exposing in the Grade 1.5 to 3.5 area ( Grade 2 ish being usual for a well exposed ) you should still have a usable filter it just may not neccesarily reflect the 'actual' grade required from a new set of filters....you will only therefore need to adjust ( down grade ) when you get a new set of ILFORD filters. I have now read that back twice and it makes sense to me, hope it does to you.

Simon ILFORD Photo / HARMAN technology Limited :