Why did you revert my edit on Dehnu's article?

Fair enough, but Dehnu clearly was a noun, so it has to have some form of declension. I'll investigate the Celtic form and see what comes up.

And can you explain why *peku doesn't have an o-grade despite being amphikinetic?

I can't.

Well, there you go! Now if you don't mind, I'll be putting the inflection table back up, based on both the Celtic and Sanskrit forms.

And what source?

I'll tell you what. This evening, I'll put in citations from both the University of Wales Celtic Lexicon and some Sanskrit dictionary.