Studying with Mr. Miwa Furuya's Chrysanthemum stamp!

I've been collecting and placing Japanese stamps stil. In order to study the classification of single-line perforation and comb perforation , I bought a manual of Chrysanthemum stamp which Mr. Miwa Furuya wrote. I bought the same manual series of Koban last year with author's autograph, however I don't have the one of Chrysanthemum. 

Now I can tell the difference of the perforation of Chrysanthemum stamp if it is block. I have little confidence on pairs and singles.

This one is comb perforated because it is beautifully crosses in the middle.
I think the pair of 1.5 sen blue I showed in the preveous blog is single-line perforation, though I'm not sure enough.