I have polylines and points of 3D model, how to create again using GH

Hello Experts,

I am trying to create a 3D model of an excavation portal for tunnel entrance, I have Coordinates and i have polylines.
But am struggling to turn it into 3D model(surfaces).
The only way i have is to break it and do lofting of small Curves. which is not right way I guess.
Please advise if you have some idea. please find attached .gh file and a picture of how it should look like.
Ajit Singh
Portal file.gh (22.0 KB)