There are some types of casting problems that could cause a surface like that, but I think they would also be visible on the top of the handle. What about the interior walls and pour lips of the skillet? Are they "pitted" as well? Maybe a detailed close-up of the skillet's surface would help.
I have never seen a Griswold skillet that appeared to have left the factory in an un-ground condition. Note that the skillet's cooking surfaces were finished in a grinding process and were not milled. Even on some pretty badly pitted pieces, I have been able to see a few of the distinct marks left by the grinding wheel, especially on the pour lips.