Help needed with Japanese text

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I’m looking for help with understanding the above fragment from Shuzo Fujimoto’s Twist Origami 1 book, page 8. You can view the complete page and the complete book here for better context.

Designs No 11-15 are not pictured in the book and are only described in a few sentences. Terms such as No 1 that appear in the text refer to other models listed in the book just before the fragment in question. I have translated the above fragment using both Google Translate and Deepl, and was able to figure out how to fold items 11, 13, and 14. However, No 12 and No 15 remain mysterious despite me spending quite a bit of time trying out various folding combinations that might fit the description.

I suspect one of the issues, apart from imperfect automated translation, may be due to problems when recognizing scanned text and converting it to characters (OCR) since the original print is of low quality. It suffices for one stroke to be wrong, and a different character may be recognized, changing the meaning completely.

The automated translations I got (not quoting in order to avoid suggesting anyone trying to translate on their own) implicate that:

• No 12 is some kind of combination between No 1 and No 5
• No 15 is about opening the center of No 1 which results in a “mirror with decorations”

The problems with these descriptions are:

• Despite trying out many approaches, I don’t see a way of combining No 1 and No 5 that would result in a nice model. It is possible, but the end result is not nice, and I doubt Fujimoto would put something like this in his book, given the quality of his other designs.
• The English text for No 15 I got from automated translation doesn’t make much sense. One possibility I see would be that it describes a general technique for making fractals from simple stars, but that’s a far-fetched interpretation (though it makes sense since I have [re?]discovered such a technique). Also, one can easily open the center of several stars, but not No 1. However, I noticed that above, Fujimoto writes the digit 1 as a simple vertical line while the 1 as written here has a bottom serif and a small line at the top - so perhaps it was another digit (maybe 4?) which is misshapen due to low print quality. Star No 4 can indeed have its center open, and I did fold a fractalized version, so maybe this is it?

I would appreciate any help if you can read Japanese and can help me with translating and understanding the above two sentences. Thank you in advance!