The backside of the wheelhouse is a made from several air vents and small cabinets.
On the site of Damen shipyards you can make a virtual tour on a stntug 1606, I made some screenshots to get more information on details and interior.
With the help of the pictures it's easier to replicate the parts
On these pictures are two steps but it needs to be three and the angled bottom plate goes until the right box.
Before the new stairs could be made the old ones needed to be removed. With new pictures of the original I could make the new ones.
Next is the airco next to the door.
The airco on the backside is 20 x16 mm.