Just to be clear, you are talking to Delion at the aetheryte plaza in Radz, and not Gerolt or the manderville assistant over in the alchemy area right? I also know that some quests only show if you are the appropriate level for them, so being on a level 90 combat class while talking to him might make a difference. Beyond that, i have no idea what the issue fix could be. He was there for me on patch day just fine, and the notes make reference to no other pre-requisites other then completing the previous Hildy step(which you would have had to do to get a Manderville weapon anyway).