I have copies of the construction drawings of the TOS shuttlecraft so I have a pattern for the corrugated surface to work from. I started with the first curvatures, rotated two of those 6 degrees until I had thirty degrees of curvatures, than copied and rotated those twice until I had 90 degrees (or a quarter of the cylinder), copied and rotated that once 90 degrees to make a half cylinder, then finally copied and rotated that 180 degrees to make the whole cylinder. Once I got going it went pretty fast. I left it at that last night and I'm left with cutting the distinctive curved end shape which I'll do this evening after work.
The rest of the cylinder was easy since it doesn't have an inboard trench like the Enterprise's
nacelles. I simply made a silhouette of half the nacelle lengthwise (minus the aft cowl) and rotated it 360 degrees. Done.
Knowing what tools you have and what they can do go a long way.
Even so once in awhile you hit something that requires tedious work.
Looking ahead the aft landing struts are going to be...interesting.