Still working on figuring out the age indicators

I haven't found any good sources for determining the ages of vintage American Tourister suitcases so I'm just working on trying to figure it out on my own.  I believe that the Tri-Taper is the oldest, the one with this kind of latch

But, that is just my guess.  Some other differences are in the handles.  There are these kind:

but I don't see many of those around.  The one I see most often is like this:

I have Tri-Tapers, Tiaras and the one that just says "Tourister" all having this type of handle.  I only have the one with that first handle pictured above (it is a Tri-Taper) so I'm assuming it is my oldest piece.
Another difference I've found is the American Tourister metal label.  Here are the two versions I've seen

again, with the later picture being the most common.