By sealed, I assume you mean in some clear plastic wrapping. I have heard of both in and out of plastic being sent to customers. Joye and DSE are the only two companies making these batts, as far as I know, and they are for all intents identical.
If by sealed you mean the atty-connection end of the batt, which is open for an auto, but "sealed" for a manual, then if you ordered manuals, they should be sealed (no hole going
through the batt for air flow).
In general, if the site says they are Joye, then they are Joye. If they do not say, just list them as 510 batts, then they may be DSE, which is also called SLB on some site. Bauway also makes 510 attys, but I don't know if they make batts.
Giving the vendor's name would have helped here, since we often know exactly what brands different vendors sell. And we could have looked at their site and gotten more info on the batts.