but I don't think you read carefully.
I've read all of the topic, but your notes keep changing, or don't fully describe what you're doing. Such as what I highlighted earlier.
I installed them again, without error. They were copied to my user fonts folder, but they are still not showing up in Font Book.
What is "them"? I would imagine the five fonts in question, but installed from what source? What installed the fonts to your user account Fonts folder? The OS will never install any fonts there. So what did?
But forget all that. Apple must have changed something in one of High Sierra's updates, and actually managed to make matters worse. Renaming the fonts no longer works. These five fonts won't show up in Font Book, TextEdit, or other Apple supplied apps no matter what you do.
The only fix now is to delete these font entirely, then grab these same named fonts from a Yosemite installation. You don't need to rename them, or otherwise goof around with the fonts to make them work. I simply dropped them into the Fonts folder of my user account, and there they were (I had already long ago removed the ones installed by High Sierra from the /Library/Fonts/ folder).
As has been the problem since it appeared in El Capitan, Apple has managed to screw up these five fonts only for themselves. Font Book won't show them, but Suitcase Fusion and other third party font managers will. Microsoft Office, the entire Adobe suite, Quark XPress and any other third party app I have can see the High Sierra installed versions. But, the apps installed by Apple with the OS don't. Or, only parts of some of the fonts.
Using the older, Yosemite copies are able to be seen by all apps. I really don't understand why Apple hasn't fixed this yet. Or, I should say, fixed it again.