Here are the results after playing with this part for few seconds
42. Extrude Curve Options:
For this next part we are going to use the extrude a little differently. Go to Surfaces - Extrude - Extrude Options. We are going to use the Distance settings, as soon you activate this Style a few things are going to change. Now we have a Extrude Length option, as well as, a Direction and a Direction Vector. Change your Direction from Profile Normal to Specify now Direction Vector is activated, Change the X Axis to Free this will turn on the input box, change it to -1 so it will go in a negative direction on the X Axis. Every time you see a vector remember that they are always laid out as X Y and Z in that order from left to right.
43. Extrude Curve:
Select the last isoparm and extrude based on example 42
44. Round Tool:
With the surfaces selected Right click and select isoparm two times. This way both surfaces isoparms are active, after this just drag your mouse over the merging curves go to Edit Nurbs - Round Tool. A yellow handle will show
45. Round Tool Modifications:
If you look at the end of the handle there are two little spheres grab one of them and drag it throws the center this will make the round toll to create a smaller tighter turn between the two surfaces .
46. Round Tool Channel Box:
If you think the transition from one surface to the next one is too big or small, just go to the channel box - open the round tool and change the number till you are happy with the results.