Hello Keith!
Thank you for giving this a 'shot'..! and congratulations!
I am still stuck at the main barrel. I am studying your file.
I wish you had left your original curves in the file so that I could see how
you went about making the shapes.

It is super encouraging to see that it can be done.
I will share my attempt as soon as I get some where : )

Please do re-post the file if you do the original curves in the file.

Speak soon.
Cheers.