At the beginning the Germans worked with an wooden design to start the Natter.
Later they came up with the steel frame tower which was installed close to Stuttgart in Germany.
Several of these launch towers should be installed to allow a constant start of Natters, but the end of the war came much faster.
So here is the second set with the steel frame tower:
Both sets can you order online, for example from here:
http://www.1999.co.jp/eng/10526321
Or if you prefer my solution, then you can buy my launch tower here:
https://www.shapeways.com/product/UXTDT7K6F/1-144-natter-launch-tower-steel-version
Or if you prefer my solution, then you can buy my launch tower here:
https://www.shapeways.com/product/UXTDT7K6F/1-144-natter-launch-tower-steel-version