Getting past Slafborn to see Widargelt...?

Patch 4.0 says a lev 60 monk has some job skills post-50 that are as yet unlearned. Erik in the goldsmith's guild, who has given out MNK quests before, says to talk to Widargelt in Mor Dhona for quests to earn the lv 52, 54, etc. job skills. Widargelt is behind a door Slafborn guards, and Slafborn bars the door unless you get his Magitaknikal Difficulties quest. You can't get that quest unless you have Magitek Armor for a mount. To get that armor you need the key that's a reward for running the Ultima Weapon quest. Ran that last year but no sign of such a key in any inventory.
Is the answer to use Duty Finder to join an 8-player raid in the Prateorium?

Widargelt is not behind the door, but on top of the wall. There are stairs leading up there nearby.