What are the details on the factory plug? I would like to get one.
Don't bother. It's cheaper and better at home depot. 7/8" Hillman plug fits perfect and is super low profile. You can paint it and it is better than the Honda plug. It's $2 it's in the section with the screws and nuts, in those specialty drawers. Here is a link:
http://www.homedepot.com/buy/hillman-7-8-in-chrome-hole-plug-881268.html