If your store install doesn't have a "More Info" button (mine didn't) simply do a Google image-search for one you like and upload it to catalog/includes/languages/english/images/buttons giving it the name button_more_info.gif

Included here is a simple one I use that fits in well with my store theme. You may wish to use it as a temporary button for this contribution if it doesn't suit you.

Full package included.

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