New type Clenporte sweet tower

[Rossi fan]

I have just stripped down a newish Clenporte M81, as it has come off site and I wanted to get the stock out.
When I got to removing the bottom segment, the black ring and spring came off attached, which normally does not happen. On close inspection, Clenporte have removed plastic from the inside section of the bottom segment. I can only assume that they have done this to make it easier to turn when full. Has anyone else seen this. My concern is the interchangeability of the segments. I have posted a pic below.

Cheers,

Paul