Pelikan has been making fantastic inks for a long time. I wouldn't doubt that they outsource inks, but at the same time I'd put my money on Pel inks being in-house. Beyond making pens, Pelikan specializes in making artist's paints, printer inks, etc etc. They make inks and paints for just about every purpose an ink or paint could fill.
With the above in mind, I'd say, if anything, it's R&K that's doing the repackaging.
One must keep in mind, a lot of manufacturers have inks that look similar to one another. Royal blue here looks similar to royal blue there. Black here looks similar to black there. etc etc