Wild guess: type 2 looks as if it is easier to manufacture.
Google search for images found an ebay seller selling
a Tetra fire extinguisher, pre-war model, which looked like type 2.
Another of type 1 had a much higher manufacturer serial number.
Serial number 80219
Serial number 44262, advertised as pre-war model
Edit: @Boehml Please read my text again, I got the numbers mixed up in the first posting,
I was in a hurry …