i have decided that the design of the vane doesn't need to be radically changed. I'm still going to be making a model of it, but this is more to get rid of the flat painting than anything else. I'm just going to make the dome at the top slightly larger to accommodate the chamber. The way i see the scene is this:

Luke enters the door and it closes, shutting R2 out. He then walks down the long shaft of the vane and the platform lift takes him up to the carbon chamber. Do we need to see him walking down the tunnel? no. Does all this need to be explained in the edit? Again, no.