I think he means the official DLC's, e'g: Battlehgorn Castle, Frostcrag Spire. Which you can get https://orders.gamesas.com/dlc/ Although my Antivirus says that there is a problem with the websites security certificate.
I was actually referring to the free downloadable content formerly on the elder scrolls website, although it's nice to get some confirmation that the purchasable DLC is still up.
And Hellmouth, what's SOL? I don't seem to recognize that acronym.