Quoted earlier : The two part case requires much more work than the traditional three-part-case.
In other words, in your earlier statement, the older models were harder to make than the current production ... ??
because you mentioned traditional, i assumed Mr. Kari that you were referring to the ie 3700, 3800, 3712, 3711, base on the illustrations.
Now, i am thinking, that both cases are probably similar in terms of production, but modern day production, the polishing of the cases, would require more attention than older production.
my thoughts.