There is a structure on the right side of the hull below the funnel. There are stairs leading down to a platform, then something behind the platform - I don't know what that is. I'm not sure whether knowing would help me know how to fold it, but I thought I'd ask. The parts are MA39 and MA47. MA 39 is the platform and its railing, but there is a part extending behind that MA47 gets combined with somehow. Here is the instruction sheet courtesy Hobby Search Japan. The two photographs showing it are side-by-side middle right.
(Well, looks like I don't know how to link in the image, here is the url:)
https://www.1999.co.jp/eng/image/10546949/70/2