Complex sentence: The diving suit worn in the story was also based on clippings that Hergé had accumulated, while the dockside bar depicted by the cartoonist is also based on an illustration that he had collected.
Split into simpler sentences: The diving suit worn in the story was also based on clippings that Hergé had accumulated. Similarly, the dockside bar depicted by the cartoonist was based on an illustration that he had collected.