Grasshoper_Mesh connection_Create approximated closed form based on 3 surfaces

Hello. I’m working on a design of a chair in Grasshopper. I would like to connect 3 different curved surfaces to get a final form of a seat. How could I transform the surface to a cloud of points in order to create one continuous mesh form? Thank you!

Chair_20191203.3dm (12.1 MB) (214.8 KB)