Who do you think wrote the journals?

Now, we may not know that much about the author of the journals right at the moment, but from what we do know about them, 1. They either have or had six fingers, and their first name starts with "F" I believe that possibly Old Man McGucket is the author of the journals. Think about it for a moment, we already know that Old Man McGucket's full name is Fiddleford H. McGucket. Also, McGucket is always seen with a cast on his left arm, and the reason could potentially be that he lost one of his fingers and is either waiting for his hand to fully heal, or he may be trying to hide the fact he had six fingers. Also, here's a YouTube of someone else who either thinks or maybe already knows McGucket is the author of the journals, but most videos on YouTube such as this one are just speculation from viewers of what they BELIEVE about specific Gravity Falls characters. The video is only 55 seconds long, but it may just very well prove that McGucket is the author. Again, I'm not certain McGucket's the author, it's just my personal theory. What's your theory on who wrote the journals, and does the information I wrote plus the information from the attached YouTube video change your mind?