How to merge faces

[infinitemach]

I have a model that I imported from an STL file. After the import I am left with a lot of faces that I would like to merge, especially the faces on the outside and inside of the cylinder. Stitch does not work, as it does not allow me to select the faces. 

How can I accomplish this?

[etfrench · Accepted solution]

Redraw it using native Fusion 360 tools.  The mesh tools are quite useful for this.

[infinitemach]

I did as you suggested and redesigned it from scratch. It worked out well and I also learned about how to create a loft between two bodies.