PGmc adverbs update

I'm sorry, I have confused myself here. So the preposition *ana, ("on, onto"), should only be Proto-Germanic *an? And I meant, did the form giving Gothic, Old High German, Old Dutch and Old Saxon *ana, ("on, onto") come from a variant of *an, possibly adverbial?

I think so, but I don't know for sure. Maybe you should read the paper yourself if you can find it?

Ah. I've read it, I just didn't know that it also applied to *ana as I didn't seem him mention it. Sorry for the confusion.