What shoul I do if I upgraded a plugin but cannot manage to join it's author?

What shoul I do if I upgraded a plugin but cannot manage to join it's author?

Hello!

I've recently worked on the json suggest plugin and enhanced the ajax functionality on it a lot. The author website is http://www.tomcoote.co.uk/jQueryJSONSuggestBox.aspx. The last update seem to be in 2008. I sent him an email to notify him about the changes but I didn't get any response.

I think my improvements are great and want to share them with the community. What should I do? Recreate it as a new plugin? I don't want it to look like I stole the code.

Thanks for your assistance
Frank-Mich