As mentioned above, I think Auto Body Specialties is just a reseller of parts (similar to Sherman & Associates here in Detroit). I'm not sure who makes their parts, but a lot of these resellers use parts from Cross Canada and Goodmark.
Goodmark does indeed make their own parts, either directly or under license. I ordered the full factory style quarter panel, and it arrived in a box marked 'CSL' or 'CSH', something like that - but no Goodmark logo. I called Goodmark, and found out this is the Chinese company that actually makes the quarters for them. The quality was
excellent, unlike some of the patch panels I bought from
other companies, where the tolerances were apparently plus/minus 2 inches.
To answer your question: The panel you buy from Auto Body Specialties (or anyone else) might, or might not, be the Goodmark panel. I would call both companies and ask.
Just my
Tom