Hi Dieter and friends!
im in contact with thomann about but  need to make sure about 2 things for these parts:

A-100 Monster Case Verbinder gerade A-100PMVG (straight)

A-100 Monster Case Verbinder gewinkelt A-100PMVW (angled)

- are these parts the latest revised versions (2016)

- and how it works ... modules should be removed to join the cases and re-installed or everything happens from the outside any close photo with the screws and the iron little thing-joiner

Kind regards