Hi,
The only way that I see it has possible is for you create a specific template for the single post of that specific CPT.
something like single-vendor.php like already exist for directory, portfolio, ect.
Depending if you want that section in the beginning or in the end you should adjust the code.
Also I just remember now that maybe it’s possible with hooks without creating the single template.
Check this article. You will have to change the code to check if it’s your custom post type.
http://www.wprecipes.com/wordpress-tip-insert-custom-content-after-each-post
Hope it helps.
-Rui