Attempting to Loft Two Complex Sketches.

[Brierley37]

Hello, 

Files attached*

I am attempting to loft two complex sketches. The sketches are made using the spline tools and are a trace of a  topographical feature. I am able to able to create a body by adding a couple of rails, but the rails are just placed roughly until the 'body will intersect' errors no longer appear, they do not create the profile I am hoping to achieve. 

Could anyone advise on a better way to reliably create a body from two sketches like this? Maybe loft settings, or surfaces or T Splines or some totally alternative method?

The part will be used for CFD and may be 3D printed in future. Conventional manufacturing or manufacturing in general isn't a concern. 

Any Advice at all on how experts would approach this task would be much appreciated. 

Thanks for your time. 

[davebYYPCU]

Break into smaller sections gets 2 out of 3 sections to work.

this end is unlikely due to this u turn in one sketch but not both.

Might help....