Codex Seraphinianus and Rohonc Codex information help

Do any of you on here know if thoose writing systems are made up, or are they actually believable to crack sometime in the future? I belive the Rohonc Codex is not made up just becasue how long its been around. But the Codex Seraphinianus just sounds not believable. Anyone?

The Codex Seraphinianus was done by an Italian artist in the '70's, Luigi Serafini. I don't think he did anything more than some good hallucinogenics instead of creating a language no one can read.

Avocado trees that walk and swim just seem like the type of thing made up under the influence.

I haven't heard of the other book. Now I'm going to have to check that out. I hope it's not as interesting as the Voynich Manuscript, I spent a whole weekend tripping out on that one. I really don't need to do that again. I spend enough time on ATS, I really shouldn't go on a wild chase over some book that can't be read.