DC-4 Pan Am

I just started this classic propliner.
S&P, scale changed to 1/160.

Question: what's the purpose of the parts on pictures 3,4,5 ? I can't figure out this.

Attached Images

	IMG_20180226_114825.jpg (1.42 MB)
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	IMG_20180226_114954.jpg (1.18 MB)
	IMG_20180226_114949.jpg (1.03 MB)