I'm making a model of the fuel bladder cavity inside an aluminum monocoque. The cavity is large enough that with careful placement I can capture most of the surfaces with the microscribe. What I can't capture I plan to mirror since it is symmetrical side to side. I've not been able to get satisfactory results using the microscribe within Shark FX so I created a spreadsheet, formatted the data, and imported as a spline. Since 3 points can define a plane I picked three points on each surface which the spline data was created from. After importing the spline I used the points in order, 3 at a time, to create a three point circle for each plane. The result is very confusing so I created layers for each plane or element enabling me to turn off the confusion.

My plan was to increase the circle diameters much larger than needed, create surfaces, mirror as required and create the model. I tried this on a 2-4-6 block with reasonable results. I'm lost with the complexity of the shape I'm trying to create and I am limited by my lack of experience dealing with surfaces. I need some general direction and tips how to proceed. The trim doesn't seem to work with varied diameter circles, the fillet surface seems to delete previously filleted parts and it gets confusing really fast with surface/surface intersections. I'm willing to start over if there is a better approach. I appreciate your input and suggestions. Thank you.
-dale