interestingly enough nobody is sure why the symbol was used in that case or when it changed meaning.

The first time I came across the German word for this symbol was pretty jarring. The word is Affenschwanz, and it does, absolutely mean “monkey tail,” which is fine and descriptive, if a little whimsical. The problem is that Schwanz is such a widely-used term for ‘penis’ that a poor Auslander might be forgiven for totally forgetting that it ever meant ‘tail’ at all and wondering what sort of madman decided to name the symbol a ‘monkey penis.’

That 1345 usage seems dubious…looks like whoever wrote that manuscript just added a flourish to the alpha character.