Grasshopper help, Unwanted Naked Edges

Hi, I’m trying to weld these surfaces together so I can apply Kangaroo effects in grasshopper but grasshopper keeps highlighting errors in my model, I am trying to get rid of unwanted naked edges by joining the surfaces in different ways, both through Grasshopper and Rhino, what am i getting wrong??? Is it something to address in Grasshopper or Rhino? I have rebuilt the model many times using different methods to try and make sure all the edges are in contact, but to no avail. As you can see in the screenshots, the red crosses highlight my naked edges.
As you can probably tell i’m very new to this so any help is appreciated.

Thanks for your time!

Hi @joan1

Try using AlignVertices then Combine&Clean

If you’re still having trouble you can upload the file here

Thanks for the response, I’ve tried your method but i’m not sure i’m applying it correctly, here are my files, if you could take a look i’d be eternally grateful!

2023_11_13_Model_03.3dm (1.6 MB) (14.0 KB)