The first form is created by combining Vahlok (mask) and Miraak's Soulgem.
It reaches its final form at the end of Shattered Legacy.
The mask is no longer associated with the Visage set as of V5, having been replaced with the Helm of Tiber Septim. As such, its place in the museum has been removed.
The display can take both the original and the replica.
You need to have the original in your inventory for the replica recipe to be available.
The first form is part of the static quest display in the Reception Hall.