When using the original Dev Aveza mod, a Legacy of the Dragonborn compatibility patch is required.
5 days after the Guild House has been built, and if the quest 'Rebuilding the Past' has been finished, Rakis will visit the museum with a gift. The gift is the Dev Aveza, the airship that will be docked behind the Guild House.
Inside the ship are a few crafting stations and sorted storage containers that are linked up with the museum Safehouse.
On the table is a manual on how to use the ship, and a map with markers that can be used for fast travel. These markers can also be used to fast travel to previously unknown locations, like directly into the Pale Pass area from 'Shattered Legacy'.